The effect of the cylinder bore deformation and piston ring tension on oil consumption was investigated under engine operating condition. At the cylinder upper area, the second order deformation caused by thermal expansion and the fourth order deformation due to head bolts showed good agreement with oil consumption using low-tension-ring. In the case of high-tension-ring, however, the correlation-coefficient between the cylinder deformation and oil consumption was lower than that of low-tension-ring. It was also found that the fourth order deformation at the lower area of cylinder showed good correlation with oil consumption.

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As a result, notable improvement in thermal efficiency was not always achieved because the occurrence of auto-ignition is localized and not so strong as to improve heat release because of lower cetane number of kerosene than DME under kerosene mixing rate of 30 % and compression ratio of 13:1. Instead, output power defined by IMEP( Indicated mean Effective Pressure) was increased by suppressing knocking or abrupt combustion in low lambda region because of low auto-ignitability characteristics of kerosene mixture. Increasing compression ratio to 17:1 did not show any remarkable improvement in engine performance.

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Recent tendency of diesel engine for passenger car is decreasing compression ratio for suiting severe emission and fuel economy regulation. The lower compression ratio is advantageous to reduce emissions. However, higher compression ratio might be better to have higher theoretical thermal efficiency. Because the Miller cycle with the late closing of intake valve gives lower compression ratio than expansion ratio, it can decrease temperature at compression end. In this report, the Miller cycle technology was adapted to a light duty diesel engine and the effects of emissions and fuel economy were examined. Using a Miller cycle, the fuel consumption and the soot emission were reduced without the penalty of NOx emission in Japanese engine emission test cycle (JE05).

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The performance degradation and the recovery in the catalytic steam reforming reaction were examined by the test pieces, using ethanol-blended gasoline contained sulfur. It was found that the reason for the hydrogen generation being maintained though sulfur existed, when there is oxygen in the recovery, is that the oxygen removes the carbon from the catalyst. The oxygen concentration and temperature on the recovery operation have confirmed to become lower with improved catalyst carrier (CZA:Ceria-Zirconia-Alumina). Even if the hydrogen concentration fell because the hydrogen generation was degraded by the use of gasoline, that was recovery by the use of E85. The hydrogen generation was not degraded when the improved catalyst is used over a period of 70 hours.

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Effect of diesel fuel properties on generation of blue and white smoke was investigated experimentally. Three types of diesel fuels (JIS#2, JIS SP#3 and GTL) were evaporated by a simple fuel vaporization device, and the concentration and color of the generated smokes were evaluated by a light transmitting smoke meter and visual observation, respectively. Concentration of blue and white smoke was the highest for the JIS#2, followed by the JIS SP#3 and the GTL. White smoke was observed at a low evaporation temperature, whereas blue smoke was observed under high evaporation temperature conditions. Moreover, relationship between the fuel property and the generation characteristic of blue and white smoke was estimated from a hydrocarbon constituent.

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In order to utilize bio-butanol as an alternative diesel fuel, the addition of a cetane number improver (2EHN) to the blend fuel of 1-butanol and gas oil was tried. And the ignitability, diesel combustion and emission characteristics of the blend fuels were investigated using a DI diesel engine. The addition of 1 mass% 2EHN sufficiently improved the ignitability of the blend fuels. When the mixing ratio of 2EHN/1-butanol/gas oil is 1/30/69 in mass%, the blend fuel has almost same ignitability and CO emission and slightly higher HC emission compared to the gas oil.

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Our Corporation has been continuously developing the fuel cell vehicle for its mass production. In this study, the cell design with porous channel, which had been found to realize the desirable reaction field of some mass transfers in the cell, was considered. The designed cell showed almost double performance as high as conventional type and brought promising prospect to achieve the fuel cell downsizing.

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This paper first analyzes the influence of the pitching motion caused by the rolling motion based on driver′s feeling in actual vehicle testing. It was concluded that the pitching motion enhances a cornering feel while driving, and the result was then utilized to develop a control law for the vehicle′s semi-active suspension, which synchronizes the rolling angle with the pitching angle. The law was further applied to a damping force control system of the vehicle. Finally, it was validated that the control law enhances a cornering feel after testing of the actual vehicle with the system.

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We developed a Preview G-Vectoring control which decelerates vehicle before it enters a curve and decelerates vehicle in coordination with vehicle lateral motion after it enters the curve. In this pre-cornering deceleration control, the predicted lateral jerk, which acts on the vehicle during cornering, is used to decelerate the vehicle. We carried out new control system equipped vehicle's test on snowy surface and confirmed that the automatic brake control quality was more than driver in views of lap time and ride quality.

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The purpose of this paper is to study the effect of body stiffness on the accuracy of reconstruction of pre-impact speed in one-dimensional collisions, and to enable more accurate reconstruction case by case than previous studies. This paper shows, by comparing body stiffness data of several types of automobiles, that the appropriate method depends on their relations. In addition, this knowledge is validated based on actual collision tests. The body stiffness data used in this study is mainly based on the data obtained in the Japan New Car Assessment Program (JNCAP).

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Establishment of useful indices to evaluate the risk of a rear-end collision is a vital issue for developing a rear-end collision avoidance assistance system. Previous researches showed that the two rear-end collision risk indices, named RP (Risk Perception) and KdB_c, were effective for identifying the limit of no-brake situations under restricted traffic conditions. In order to use the indices appropriately, it is necessary to understand to what extent the indices reflect the risk of a rear-end collision. This paper investigates driver brake timing for avoiding a rear-end collision by analyzing real world driving data on general roads. The driving data contains wide varieties of traffic conditions. The results show that the two indices are effective when the velocity of the preceding vehicle is not less than 30km/h. However, there are situations in which non-emergency braking is done beyond the threshold values of the indices. This paper mentions possible reasons for the occurrence of those situations based on driver behavior analyses.

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Sun glare adversely affects traffic conditions, so traffic safety measures for vehicle against sun glare have been implemented. But quantitative analysis by vehicle type of the influence of sun glare on traffic accident occurrence has not been carried out. Using the traffic accident data in Chiba Prefecture which include accident latitude and longitude, vehicle travel direction, we determined how much the sun glare affects traffic accident occurrence. So drivers of first car concerned were adversely affected by sun glare, but degree of affection by sun glare depends on each vehicle types.

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In a vehicle-to-vehicle communication safety driving support system, various experiments were executed to investigate influence on normal drivers in the possible situations caused by errors of measured vehicle positions. In the experiments, several situations, for example timing change of support information, were simulated by a driving simulator. The contents and results of the experiments are reported.

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Drowsy driving has a large risk for serious accidents. It is important for preventing these accidents to warn drivers of their low state of arousal. This paper describes the capability to estimate the arousal level from the area of pupil. We carried out experiments to measure the area of pupil on a driving simulator. The results showed that it has a strong correlation with the level of sleepiness. The difference of the areas of pupil was significant between the state of arousal and that of sleepiness where lane departures could occur.

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This paper investigates the relationship between driver′s arousal level and eye-fixation-related potentials (EFRP) while driving. The experiment with driving simulator was conducted and the subjects were required to perform monotonous driving task, while measuring their electroencephalogram (EEG). Their arousal levels were evaluated based on the subjective questionnaire, alpha wave-power and lateral deviation. The results indicate that the peak amplitude of lambda response of EFRP decreases when the driver′s arousal level decreases. Furthermore, these results imply that EFRP would be a valid index estimating the driver′s behavior in lower arousal level.

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An experiment was carried out in an instrumented vehicle in order to evaluate forward vehicle collision mitigation systems. In this experiment, first we examined how drivers respond to forward vehicle collision warning systems when the expectation of a hazardous situation is low. Based on the experimental data, we calculated the amount of decreases in collision speeds by using the system. Finally, we tried evaluation of decrease rate of death/serious injury accidents in addition to the reduction rate of traffic accident.

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As part of NEDO Energy ITS Project, we aim to establish reliable international evaluation methods to estimate CO₂ reduction using various ITS applications. To evaluate CO₂ reduction, we developed a mesoscopic CO₂ emission model. The concept of our emission model is the estimation of CO₂ emissions based on drive energy which is one of the most important factors to predict fuel consumption. We are considering the energy of acceleration by using statistical method. This model has good accuracy, which is verified by the comparison between measured and predicted fuel consumption.

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In recent years, measuring exhaust emissions from in-use vehicles on the road using an on-board exhaust gas measurement device (Portable Emission Measurement System (PEMS)) has been studied in Europe and the United States to confirm the correct operation of exhaust emission control systems under actual vehicle operations. Two emissions evaluation methodologies are proposed, the NTE control area method from the United States, and the Average window method from European Commission. In this report the both methodologies are compared under actual Japanese vehicle operation, using several heavy trucks meeting recent Japanese emission regulations. The results indicated that the Average window method is better than the NTE control area method for Japanese vehicle driving conditions.

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To achieve the low carbon society, the evolution of internal combustion engine efficiency and the addition of electric devices have been required. As a result, control systems have become more complex, which in turn, demands improvement of development efficiency. In this study, the new plant model and new virtual environment are established for the purpose of improving the efficiency of the control system development. Furthermore, by using the new modeling method, the improvement of development efficiency of the plant model and virtual environment is made possible.

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The conventional vehicle suspension consisted of damper and coil spring is replaced by a colloidal cylinder, which accommodates a colloidal solution obtained as a mixture of lyophobic nano-porous silica gel powder and water due to the action of the surface tension. Firstly, the ride comfort was investigated by a single degree-of-freedom suspension bench device, and analyzed basic characteristics "stroke-load" by the single bench device. Then, the ride comfort and the rolling attitude were experimentally evaluated from random excitation and travel tests on a passenger car. A through comparison between the performances of conventional suspension and the proposed colloidal cylinder was performed.

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A nondestructive evaluation method for delineating the solidification boundaries of arc weld in thin steel plate is developed by using a nonlinear ultrasonic imaging technique. With the nonlinear ultrasonic technique, the higher harmonic amplitudes at solidification boundaries appear high. The estimated solidification boundaries are close to the contour line obtained by the conventional macro photographs. Thus, the conventional destructive observation of the depth of welding could be replaced by the nonlinear ultrasonic imaging technique.

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In the following driving in the general road, about 70% of all drivers are worse fuel economy than the ACC control by Performance Index for Approach and Alienation (KdB-ACC). But they will get good fuel economy in actual traffic by using KdB-ACC. Furthermore, selecting Eco-mode of KdB-ACC, they will get the good fuel economy of about 8% of averages (maximum of about 20%) to Normal-mode of KdB-ACC in actual traffic.

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