Braking tests under low speed braking conditions were conducted on the brake tester to evaluate the brake torque variation (BTV). In order to reveal the mechanism of the mode showing the largest BTV of the wave disc, the applied fluid pressure and the elastic deformation of the brake pad were measured. This study found that the crucial BTV of wave disc was caused by the deformation of the pad, while the BTV of conventional circular disc was caused by fluid pressure variation. Current paper proposed an effective method to prevent the torque amplitude at high order of BTV.

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This paper proposes an automatic parking system to reduce burden of vehicle driver. A target parking position is selected automatically from empty space in a parking lot. To find the empty space the parked vehicles are recognized based on distance information measured by an in-vehicle 3-dimensional range finder. The optimal trajectory is generated to minimize rate of change of curvature. The effectiveness of the proposed system is verified by simulation and experimental results in parking lots.

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Continuous Variable Valve Event and Lift system(VVEL) which improves three major engine performaces (fuel consumption/emission/driving performace) in well-ballanced manner, is developed. This paper introduces outline of the VVEL system, and describes the principle of operation/transformation and the mechanism of improvement in engine performance of this system.

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We have developed a measuring method that can measure liquid fuel (= wet) distribution in a cylinder under transient state. The features of this method use fuel-fluorescer mixture and capture in-cylinder wet distribution by using CCD camera that was irradiated by ultraviolet source. In this paper, we observed the process of in-cylinder wet distribution during 4cycle from cranking start, and effect of injection timing and coolant temperature. And we clarified the wet on the exhaust cylinder-liner had the highest degree of incidence to unburned hydrocarbon emitted form gasoline engine.

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For the next generation low emission vehicles, the Super Clean Diesel (SCD) Engine has been researched and developed. Many devices using the concept of high boost and wide range and high EGR are installed in the 6 cylinder engine. Both the low-pressure loop EGR system and the high-pressure one are adopted for the reduction of NOx and PM with the higher EGR rate. In this study SCD Engine is tuned by steady state test and finally the SCD Engine is tested by JE05 transient test cycle.

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We modified calculation model of clutch mating plate heat deformation for wet multiple plate clutches on second report. The criteria of this heat deformation were made clear by modified calculation model. The actual operation on the vehicle where clutch surface temperature T reach these criteria assumed to be that large energy was absorbed during short time like inching-fullreverse operation. This assumption was proved by actual bench test. The difference of clutch damage tendency that were returned from the field was cuased by difference of criteria between clutch mating plate deformation and clutch friction material damage.

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Tensile-shear test, fatigue test and corrosion test are carried out on clinched joints of 6063-T5 aluminium alloy plate. From fatigue test, two different fatigue fracture morphologies which are base metal fracture and joint fracture are observed. The ratio of the plate width to the notch width (w/a) are used to classify the fracture morphologies and classification value are obtained. A tensile-shear test and a fatigue test are carried out about clinched joints exposed to SST1000h or CCT120 cycles. It is found that effect of corrosive environment on the static tensile-shear strength and fatigue strength of clinched joint is small.

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The Adaptive Front Lighting System(AFS) for four-wheeled vehicles has been introduced.
Japanese motorcycle manufacturers have presented AFS-mounted prototype motorcycles. When a motorcycle is driven on a curved road, the motorcycle headlamp inclines horizontally as the motorcycle body banks, and the area illuminated by the headlamp becomes limted. Therefore, minimizing the horizontal inclination of the headlamp would improve the visibility.
This study was conducted to clarify the effects of a system to adjust the horizontal inclination of the motorcycle haedlamp(motorcycle AFS) on visibility, and to examine the side-effects of the motorcycle AFS(the discomfort glare for oncoming drivers).

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An automatic feed forward braking and steering control is studied to avoid an obstacle available when it is impossible for the driver to avoid it. The vehicle is regarded as a mass and the required path curvature to accomplish a lane change is calculated under the condition that the lane change width, length, and initial vehicle velocity are known. Moreover, the required front-wheel steer input is obtained by solving an inverse response to the target lateral acceleration given by the curvature. The response to the calculated steer input is studied with the full vehicle model computer simulation.

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Brake Squeal is caused by dynamic unstable structure and friction force variation. Recently, FE Analysis for brake squeal reduction is applied for brake design refinements, which depends on the dynamic instability theory. On the other hand, friction force variation reduction has not been studied sufficiently before, because the reduction of friction force variation is very difficult. In this paper, molecular dynamics is applied for polymers in friction materials. This MD simulation result of friction force in polymer is validated by some experimental data. This paper shows the possibility of brake squeal reduction by friction materials design concept.

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Aerodynamic coefficients and pressure distributions of flow around a vehicle model of 1/20 scale were measured by using wind tunnel test. Numerical simulations of flow around the vehicle model were executed by using Large Eddy Simulation (LES) with Dynamic Smagorinsky Model (DSM) under the same conditions as the experiment. As the comparison parameters, the yawing angle was changed from 0 to 30 degrees every 10 degrees, and the experimental and numerical results were compared. Pressure distributions were accurately computed by using Large Eddy Simulation around the vehicle model in case of yawing angle of 0 degrees. However, in case of yawing angle of 30 degrees, the laminar separation around the sharp edges of the frame of windshield could not be calculated accurately enough. Therefore, the computational accuracy of the aerodynamic coefficients has decreased.

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This paper describes a new catalyst powder structure that inhibits the sintering of the precious metals used in emission control catalysts even under vehicle aging conditions and keeps their particle size in the single-digit nanometer range. This catalyst powder structure consists of a support material for stabilizing precious metals by promoting their chemical bonding and a wall material that physically inhibits aggregation of support material particles. This new structure makes it possible to halve the precious metal loading compared with that of conventional catalysts, while providing the same level of catalyst conversion performance.

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Nitrous oxide (N₂O) emission from urea SCR vehicles is invstigated by both engine and vehicles tests. Emission level of N₂O in JE05 test cycle is 0.36 to 0.43g/kWh, that is equivalent for 15-20% of global warming effect for CO₂ emission. From test results of the engine without post DOC, 80% or more of N₂O is formed by oxidization of NH₃. N2O emission from urea SCR may increase, if SCR catalyst is deteriorated and NH₃ adsorption capacity decrease, or if NOx reduction techniques such as rising catalyst temperature to meet '09 emission regulation are installed.

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The dead time and disturbances in the process of intake air control are some of the adverse factors that induce poor idle-speed control response and stability. In this paper, a mean-value engine model with dead time and disturbances is constructed. Two control methods, a modified Smith predictor and sliding mode control were investigated. Transition disturbances before and after the dead time and engine speed fluctuation were added to the simulation. From the simulation results, the shorter adjustment time and the lower deviation for rejecting disturbances are obtained by applying the sliding mode control.

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Effect of impurities of fuel, which are worried to mix during producing and delivering when DME fuel for vehicles is put on a market, on DME powered diesel engine performances were investigated with negligible emission DME engine installed a common-rail fuel injectin system by partial load stable mode and Japanese transient mode(JE05 mode) test. Water has a most harmful influence on increasing unburned emissions and formaldehyde. Blending FAME increase CO emission in low excess-air ratio conditions, and HCs emission is increased compared to other impurities. Propane mixing increase THC slightly in medium load conditions. Methanol mixing increase THC and CO emissions slightly in low excess-air ratio conditions. Oxidation catalyst cannot decease CO, THC and formaldehyde emissions when the catalyst temperature isn't enough high. However, any tendencies of impurity's effects on emissions cannot catch by JE05 mode test.

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Compared with a straight pipe, the sound pressure level of flow noise in abrupt-expansion pipes was larger for certain expansion length. The flow noise level hit maximum when the reattachment region coincided with the location of the open end of the expansion pipe. It is considered that the noise source was generated by the eddy collision on the edge of the open end of the expansion pipe. The expansion length for the maximum noise level was generalized using the ratio of the expansion length L to the expansion diameter D, irrespective of the expansion diameter and the flow velocity.

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Supercharging is an effective means of increasing the load of a homogeneous charge compression ignition (HCCI) engine, but its effect on combustion is still not clearly understood. This study examined the influence of the intake air pressure on the low- and high-temperature reactions of an HCCI engine operating on DME and methane. A chemical kinetics simulation was also conducted. The experimental results showed that combustion became more moderate as the intake air pressure was increased. Moreover, the mixing ratio of DME and methane changed the rapidity of combustion under high intake pressure operation.

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The objective of the present study is to reveal what factors affect the slip. The slip speed was observed using devised elements and radial displacement sensors. The relationship was revealed between the transmitted torque and the belt penetration in the pulley groove. The motion of belt elements in the pulley groove was observed by a high-speed video camera. When a clearance between elements exists, power cannot be transmitted as long as enough elements are not supplied into the active arc. Therefore, slip occurs in the active arc while the elements move with the pulley without slippage in the idle arc.

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The new particle number emissions regulation will be applied from 2011 in Europe. Simplified measurement systems will be necessary to develop the vehicles. We removed some uncertain factors that consist in the current particle number measurement and developed the particle number measuring system of lower cost based on particle number characteristics investigation, and the performance was confirmed equal to the PMP conforming device as a result of the comparison evaluation. In addition, we investigated correlation of particulate mass and particle number of gasoline vehicles.

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Since the PCI combustion is limited by strong knock at high load condition, a conventional diesel combustion is normally used. However simultaneous reduction of NOx and SOOT emission is difficult in the conventional combustion because its characteristic of the mixture has broad band of equivalence ratio distribution. Therefore homogenize of a mixture is required even though a conventional combustion. Thus 300MPa capable, the ultra high pressure injection system was made as a proprietary device for improvement of turbulent mixing rate and engine testing was conducted by using this.

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The authors have shown that it is effective to reduce BSNOx and PM by high rate EGR. But it is not easy that the wide range and high rate EGR is achieved in high boosted and inter-cooled diesel engine, because increasing of EGR flow in high pressure loop decreases total flow passing turbocharger. The combination system of both high and low pressure loop EGR is able to increase EGR rate and boost pressure in comparison with a case of only high pressure loop EGR system, and it reduces exhaust emissions and fuel consumption effectively.

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In previous study, effects of butylated hydroxytoluene (BHT) as an antioxidant on oxidation stability of biodiesel fuel have been evaluated through the accelerated oxidation test. Also, improvemnet of auto-oxidation stability by addition of d-limonene, derived from orange oil, have been discussed based on the result of long-term aging test. The main prupose of this study is to clarify the antioxidants suitable for 5 wt-% biodiesel blend(B5). Effects of several kinds of antioxidants were evaluated by measuring induction period of peroxide IP, increase in acid value, peroxide value and kinematic viscosity during acclerated oxidation process. Also, a relationship between B5 and neat FAME on oxidation stability with antioxidants with investigated.

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A permenent magnet DC brushless motor is the most suitable for high torque electric power steering. Unlike brush motors, these motors can be driven up to high revolution speeds by using field weakening control that reduces the magnetic flux. However, vibration caused by this field weakening control occurs in an 8-pole 9-slot DC brushless motor. Therefore, the issue is that high power and low vibration must be compatible. The authors focused on this issue, and investigated the mechanism of the vibration. This paper proposes a countermeasure based on the results of this investigation, and reports test results of reduced vibration.

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Encounters between big game, such as the moose, and private cars often result in severe injuries and death. A vehicle-based moose detection early warning system is a technical countermeasure to increase the traffic safety by alerting the driver in case of danger. Based on available off-the-shelf consumer electronics, a infrared night vision system was built to serve as a platform for experiments with moose early warning driver assistance systems. Aspects of a moose thermal replica employing a horse are discussed and typical vehicle-moose movements are directed and recorded to form a publicly available database for research and education.

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Our research objective is to clarify the effect on the utiliztion of automotive diesel fuels made from wider variety of blend stocks to the latest vehicle technologies. The target properties studied are mainly cetane number and cyclic compounds(aromatics and polycyclic naphthenes, etc). Cetane number was widely varied from 35 to 82. The types and concentrations of cyclic compounds were also changed widely. Two diesel engine systems equipped with diesel particulate filter (DPF) were used in this study, which are compliant to the Japanese New Short Term Regulation, New Long Term Regulation respectively. Wide varieties of transient driving modes were selected for better understanding under real world driving, and emissions from both upstream and downstream of DPF in each driving mode were examined.

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The long-term energy demand/supply structure and CO₂ emission reduction in Japan are evaluated assuming adoption of the next generation vehicles such as HEV, PHEV and BEV in the passenger market. The national target of 30% improvement of energy utilization efficiency and the transportation sector target of lowering oil dependency to around 80% would be attained by such an adoption scenario. Energy and environmental characteristics of the next generation vehicles and total costs of owning such vehicle are also evaluated for the average registered/light vehicles.

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The improvement of the simulation accuracy of driving simulators enhances the effect to utilize them in research and development. Most visual systems are required to provide more real images and wider field of views, therefore visual display systems has become to be large. It is also necessary that a display system is rigid and light if it is located on a motion system. This paper describes the specifications and the design process of a visual display system which has a dome screen and is located on a motion system

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