Transactions of Society of Automotive Engineers of Japan
Online ISSN : 1883-0811
Print ISSN : 0287-8321
ISSN-L : 0287-8321
Volume 48, Issue 4
Displaying 1-27 of 27 articles from this issue
Research Paper
  • Tomohiro Iwatsuka, Shunsuke Tsuga, Masaru Kano, Yoshiki Inoue, Kiyoter ...
    2017 Volume 48 Issue 4 Pages 789-794
    Published: 2017
    Released on J-STAGE: May 15, 2018
    JOURNAL FREE ACCESS
    Pre-ignition caused by spark plug was investigated visually by using an actual engine. As a result, two types of pre-ignition were confirmed, which are heat surface ignition at high revolution and non-heat surface ignition at low revolution. For the latter phenomenon, presumption of the ignition location, investigation of engine parameter sensitivity and comparison of occurrence condition with LSPI caused by red-hot particles were carried out for these pre-ignition.
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  • Akira Matsumoto, Yoshimitsu Kobashi, Satoshi Kato, Kaname Naganuma, Ta ...
    2017 Volume 48 Issue 4 Pages 795-800
    Published: 2017
    Released on J-STAGE: May 15, 2018
    JOURNAL FREE ACCESS
    A mixed fuel consisting of gaseous fuel and liquid fuel can realize flash-boiling injection even under in-cylinder condition close to top dead center. This study mixed liquefied ethane into gas oil and applied the mixed fuel into diesel engine to offer improved engine performance. The flash boiling effect that enhances spray atomization and evaporation promoted lean mixture formation, and achieved low soot and low NOx combustion without EGR while improving thermal efficiency. In addition, the effects of flash boiling were investigated by comparing the combustion characteristics between the ethane mixed fuel with flash boiling and the Shellsol mixed fuel without flash boiling.
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  • Kenji Sugata, Sejun Lee, Takeshi Yokomori, Norimasa Iida
    2017 Volume 48 Issue 4 Pages 801-806
    Published: 2017
    Released on J-STAGE: May 15, 2018
    JOURNAL FREE ACCESS
    Combustion regimes of super lean-burn were investigated in order to realize stable combustion for every cycle. Laminar burning velocity, flame thickness, turbulent intensity, and integral length scale were calculated, and the crank angle history of turbulent Karlovitz number was shown on the regime diagram for premixed turbulent combustion suggested by Peters. The result showed that the effect of quenching due to flame stretch is larger during initial combustion duration because turbulent Karlovitz number is larger in super lean-burn conditions, and an interpretation was given regarding the combustion regime of super lean-burn different from general flame propagation.
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  • Masahiro Ozawa, Kyohei Yamaguchi, Norifumi Mizushima, Hisakazu Suzuki, ...
    2017 Volume 48 Issue 4 Pages 807-813
    Published: 2017
    Released on J-STAGE: May 15, 2018
    JOURNAL FREE ACCESS
    In diesel vehicles, the suppression of the exhaust emission at the real driving has become an urgent task. In this study, in order to clarify the requirements of exhaust gas evaluation methods at the time of the real driving, the variation factors on NOx emission from a diesel passenger vehicle were investigated under the real driving using the portable emissions measurement system (PEMS). Further, for the purpose of evaluating real driving emissions data properly, the method to normalize the NOx emission under the real driving and predict the emission during JC08 mode test using the NOx emission map created using data obtained from the real driving was considered.
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  • Naoto Mizobuchi, Eriko Matsumura
    2017 Volume 48 Issue 4 Pages 815-820
    Published: 2017
    Released on J-STAGE: May 15, 2018
    JOURNAL FREE ACCESS
    Post-injection has been attracted attention as the Diesel Particulate filter regeneration method. However oil dilution caused that fuel spray impinges oil film on cylinder liner has seen as a problem is an issue which cannot be ignored. Because oil dilution is leading to deterioration of sliding properties of piston and thermal efficiency, there is need to clarify spray impingement behavior on oil film. In this study we simultaneous measured deposition amount of diesel spray impinging on oil film and oil film thickness using Double Laser Induced Fluorescence method. As the result of measurement using DLIF method, it was found that a large difference of amount deposition of fuel spray impinging on dry wall and oil film.
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  • Ken Mase, Kimihiro Fukawa, Masao Kinoshita, Hiroshi Moritani, Hitoshi ...
    2017 Volume 48 Issue 4 Pages 821-826
    Published: 2017
    Released on J-STAGE: May 15, 2018
    JOURNAL FREE ACCESS
    In order to clarify the effects of ethanol fuels on intake valve wear, wear measurements utilizing a radioisotope technique have been performed. The results indicated that wear tended to increase when the cooling water temperature was low. To identify the cause of the wear increase, we measured the concentration of acid in the exhaust gas, analyzed deposits adhering to the valve, and observed the area around the intake valve. Based on the results, it was concluded that intake valve wear increased due to the presence of an acidic liquid film adhering to the valve surface.
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  • Takahiro Inoue, Taichiro Tamida, Takashi Hashimoto, Noboru Wada, Akira ...
    2017 Volume 48 Issue 4 Pages 827-832
    Published: 2017
    Released on J-STAGE: May 15, 2018
    JOURNAL FREE ACCESS
    The addition of ozone gives the improvement of the combustion stability to a part of HCCI combustion conditions. We manufactured an intake in-line type ozonizer for a gasoline engine, and evaluated the effect to HCCI transient combustion by a single cylinder engine. In this presentation, we report the features of the developed ozonizer and the results of the HCCI combustion experiment.
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Technical Paper
Research Paper
  • Shingo Koumura, Takahiro Shionoya
    2017 Volume 48 Issue 4 Pages 845-851
    Published: 2017
    Released on J-STAGE: May 15, 2018
    JOURNAL FREE ACCESS
    A dynamics model considering series rigidity was constructed to examine suspension friction, which has a major effect on ride comfort on paved roads. The friction characteristics of the bushings, ball joints, and shock absorbers are expressed with series elastic elements such as arm rigidity and the spring constant of the oil seals. It was confirmed that the calculated values for the overall spring constant and damping coefficient of the suspension virtually matched values measured in a 4-post shaker test. In addition, the results of analysis using this dynamics model confirmed that the degree of friction affects both the damping coefficient and the spring constant of the suspension, especially when the series rigidity is high. Also highly rigid friction has an adverse effect on sprung motion in frequency ranges above 15 Hz. After suspension enhancements were adopted based on these findings, 4-post shaker tests confirmed that the targeted effect was achieved.
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  • Kanako Nemoto, Yuji Enomoto, Yasuyuki Saito
    2017 Volume 48 Issue 4 Pages 853-858
    Published: 2017
    Released on J-STAGE: May 15, 2018
    JOURNAL FREE ACCESS
    To reduce vibration and noise of motors, restraining vibration induced by electromagnetic force is necessary. In this report, we focus attention on axial mode shapes of the stator core and relationships with electromagnetic force harmonics and propose a method to restrain electromagnetic vibration by three-dimensional electromagnetic field construction to change electromagnetic force harmonics amplitudes and phases in the axial direction of the motor. The result of the calculated acoustic power level reduction was obtained by applying one rotor configuration based on the proposed method to an actual motor excited by radial electromagnetic force harmonics.
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  • Yasuhiro Akagi, Pongsathorn Raksincharoensak
    2017 Volume 48 Issue 4 Pages 859-865
    Published: 2017
    Released on J-STAGE: May 15, 2018
    JOURNAL FREE ACCESS
    This paper presents a path planning method for driver assistance systems in mixed urban scenarios. We proposed an inverse collision probability model based motion planner to generate the trajectory, including the positions to path through multiple traffic participants. To design the probabilistic models which represent an obstacle avoidance maneuver, we collect and analyze driving data of expert driver. Then, we conceder the direction and the value of time to collision of the target traffic participant. Then, we show the difference of driving behaviors of the expert drivers according to the difference of the direction of the target. The proposed method generates the optimal trajectory plan by using the global optimization algorithm named Belief Propagation. Finally, we show the evaluation experiment that compares the difference between the trajectories generated by the proposed method and natural driving data.
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  • Yuma Mouri, Motoki Shino, Noboru Kubo, Katsuhiko Oshikawa
    2017 Volume 48 Issue 4 Pages 867-872
    Published: 2017
    Released on J-STAGE: May 15, 2018
    JOURNAL FREE ACCESS
    This study proposes an avoidance method of crossing collision of micro electric vehicles (MEV) based on the prediction of collision forms. Avoidable space is considered in the method and the avoidable space is influenced by the intersection shape and the behavior of crossing vehicles when they avoid the other vehicles by accelerating, decelerating and steering. In this paper, the authors made such articles clear for this method as the MEV’s braking level, the decelerating crossing vehicle into an intersection and the effect by a cross angle of the intersection.
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  • - The Evaluation by the Drivers (36~57 Years Old) -
    Masato Gokan, Yoshiro Aoki, Nobuhisa Tanaka, Makoto Yasumoto, Satoshi ...
    2017 Volume 48 Issue 4 Pages 873-878
    Published: 2017
    Released on J-STAGE: May 15, 2018
    JOURNAL FREE ACCESS
    In Japan, the number of the traffic fatal accidents in the night accounts for about half of the whole number of the traffic fatal accidents. In part because it is difficult for driver to recognize pedestrian in night-time. In order to reduce the fatal traffic accidents, it would be effective to improve the conspicuity of pedestrian. In this study, the change of the conspicuity of pedestrian by the illuminated area of the headlight was analyzed by subject experiment. We were able to clarify the conspicuity of pedestrian when the driver (36-57years old) looked at the pedestrian in night-time.
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  • Kei Nagasaka, Koji Mizuno, Daisuke Ito, Naoya Saida
    2017 Volume 48 Issue 4 Pages 879-884
    Published: 2017
    Released on J-STAGE: May 15, 2018
    JOURNAL FREE ACCESS
    When optimizing occupant protection, it is important to consider how each structure develops crush forces so that the passenger compartment acceleration can be controlled. In this research, a new Energy-Derivative Method was developed to analyze the acceleration of the passenger compartment using the contributions from the individual structures. In the full-width crash test, the contributions of the crush box and front side member were initially large, on the contrary the contribution of the passenger compartment deformation was large in the final phase. In the ODB test, the contributions of the honeycomb and the passenger compartment were large.
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  • Koji Tanida, Masahiro Kimura, Yuichi Yoshida
    2017 Volume 48 Issue 4 Pages 885-890
    Published: 2017
    Released on J-STAGE: May 15, 2018
    JOURNAL FREE ACCESS
    The purpose of this research was to study the process of formation of collaborative merging behavior in an expressway-merging-area, and to propose merging schemes for autonomous vehicles based on this process. Vehicle positions and speeds were analyzed with high accuracy using digital image processing to videos of vehicles in an expressway-merging-area taken from an elevated position. Three merging patterns were identified as a result. The results suggest that merging patterns are decided collaboratively, with drivers taking into consideration whether the priority is for direct merging or for yielding when the merging vehicle is at the tip of the hard nose.
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  • Yuichi Uchida, Daisuke Ito, Koji Mizuno
    2017 Volume 48 Issue 4 Pages 891-896
    Published: 2017
    Released on J-STAGE: May 15, 2018
    JOURNAL FREE ACCESS
    In car accidents, components and restraint systems around the occupant can cause severe injuries to the abdomen area. Damage to the liver, the largest internal organ, can result in large amounts of bleeding, leading to fatal injuries. In this study, a liver model with internal blood vessels was developed and validated by dynamic compression ex vivo. Then, impact tests were conducted on a full-body human finite element model containing the liver. Finally, a side impact collision was simulated with the human model seated in the car, and liver deformation as well as internal injury caused by the blood were investigated.
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Material
  • Takashi Suzuki, Takashi Wakasugi, Masahiko Kato, Koichi Fujita
    2017 Volume 48 Issue 4 Pages 897-902
    Published: 2017
    Released on J-STAGE: May 15, 2018
    JOURNAL FREE ACCESS
    Pedestrian-vehicle accidents are a major problem in Japan. In 2011, ITARDA reported that approximately two-thirds of fatal accidents of pedestrian occurred at night. Autonomous Emergency Braking System (AEBS) for pedestrian is expected to be a countermeasure against the problem. Test of the AEBS for night pedestrian will begin immediately. In this study, the illuminance around the fatal accident points at night were measured for the purpose of formulation of the test protocol since no statistical data exists. It was clarified that the illuminance was within the range of 2-46 luxes at City, and there were many points under 0.5 luxes at interurban by field survey.
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Research Paper
  • - Time Prediction to Regain Driving Control, Using Driver’s Visual Behavior Metric and Task Demand -
    Hiroshi Kishi, Motoyuki Akamatsu, Terumasa Endo
    2017 Volume 48 Issue 4 Pages 903-908
    Published: 2017
    Released on J-STAGE: May 15, 2018
    JOURNAL FREE ACCESS
    EORT (Eyes-off-road time) as a metric of driver’s readiness to take over driving was investigated, under automated driving condition in curves using a fixed driving simulator. Two experiments were carried out. In first experiment, it was found that drivers tended to reduce EORT, according to the increase of driving task demand characterized by radius of curvature when they were aware of taking over. This trend was same as in manual driving. Time prediction to regain normal steering control by use of EORT metric after the sudden taking over was also experimented. It was found that multiple regression equation including both task demand, and EORT, may predict the time to regain normal steering control. Consequently, it is suggested that both EORT and task demand are to be included in a metric of readiness to estimate time to regain driving control.
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  • - Information Methods and Driver's Response -
    Ryohei Homma, Takashi Wakasugi, Kenji Kodaka
    2017 Volume 48 Issue 4 Pages 909-914
    Published: 2017
    Released on J-STAGE: May 15, 2018
    JOURNAL FREE ACCESS
    This driving simulator study was investigated drivers' ability to resume manual control from a level 3 automated vehicle. Participants were asked to engage in tablet task while automated driving. Take-over request (TOR) was provided to drivers at a construction site in each condition: TOR timing was set 10s/ 20s/ 30s and types of information were set auditory +visually/ +braking/ +voice/ +braking and voice. Improvement of driver perception, cognition, operation and vehicle behavior were demonstrated in each condition. However, in our experimental conditions, not all the drivers could pass the construction site without collision. Therefore, investigation of the transition strategy is required in future work.
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  • - Typical Pattern Classification of Pedestrian Collision Scenes and a Case Study on Car-following Right Turn Scenes -
    Motoki Shino, Hiroshi Yoshitake, Yuta Shimazu, Nobuyuki Uchida, Minoru ...
    2017 Volume 48 Issue 4 Pages 915-920
    Published: 2017
    Released on J-STAGE: June 25, 2019
    JOURNAL FREE ACCESS
    Towards prevention of traffic accidents involving pedestrians, the objective of this study is to construct a pedestrian collision risk assessment method of right turn at intersections for driver assistance systems based on driving behavior indices related to drivers’ risk anticipation. In this paper, we first clarified traffic environment elements affecting right turn driving behavior and classified typical patterns of pedestrian collision scenes. Next, we focused on car-following right turn scenes as a case study and examined driving behavior indices regarding drivers’ risk anticipation and validated the indices through a risk scene reproducing experiment using the JARI-ARV.
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  • - Drivers’ Visual Search Behavior Features Affecting Pedestrian Collision Risk -
    Hiroshi Yoshitake, Motoki Shino, Hisashi Imanaga, Nobuyuki Uchida
    2017 Volume 48 Issue 4 Pages 921-926
    Published: 2017
    Released on J-STAGE: June 25, 2019
    JOURNAL FREE ACCESS
    Towards prevention of traffic accidents involving pedestrians, the objective of this study is to construct a pedestrian collision risk assessment method of right turns at intersections for driver assistance systems based on driving behavior indices related to drivers’ risk anticipation. In this paper, we focused on 2 typical right-turn pedestrian collision scenes, one with no other traffic participants and the other with oncoming vehicles, and extracted risk assessment indices based on near-miss incident analysis. The extracted indices were validated through a risk scene reproducing experiment using the JARI-ARV and driving behavior features affecting collision risk were examined based on the results.
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  • Daichi Katoh, Yoshimitsu Hashizume
    2017 Volume 48 Issue 4 Pages 927-932
    Published: 2017
    Released on J-STAGE: June 25, 2019
    JOURNAL FREE ACCESS
    An air-dam spoiler, which is widely equipped under the front bumper, is known to be one of the most effective aerodynamic devices to improve vehicle aerodynamic performances. However, the mechanism to control the aerodynamic characteristics has not clarified completely. This paper revealed fluid dynamic mechanism of the aerodynamic drag reduction regarding a small hatchback type passenger car. In this research, we investigated the mechanism by comparing the drag change to the flow structure change of the wake by PIV measurement. Finally, we explained clearly the mechanism of the drag reduction from the point of view of the wake structure change.
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  • Yasuhide Nishihori, Hideki Kato
    2017 Volume 48 Issue 4 Pages 933-938
    Published: 2017
    Released on J-STAGE: June 25, 2019
    JOURNAL FREE ACCESS
    Ultra-compact electric vehicles are expected to be widely used, not only to realize environmentally friendly transportation but also to ensure mobility in areas with low levels of public transport services. Especially in highly and mountainous areas, the difference in height between the origin and destination point affects energy consumption. However, the report mentioned from this point of view is rare. In this research, we report the result of analyzing the relationship between real-world utilization characteristics and energy consumption of an ultra-compact electric vehicle in a local city.
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Technical Paper
  • Norihiro Kanno, Jun-ichi Hamada, Nobuhiko Hiraide, Atsutaka Hayashi, A ...
    2017 Volume 48 Issue 4 Pages 939-943
    Published: 2017
    Released on J-STAGE: June 25, 2019
    JOURNAL FREE ACCESS
    In the study, for the purpose of conserving resources, Nb-free and Cu-added ferritic stainless steel sheet with excellent heat resistance was developed. The chemical composition was decided as 14%Cr-1.2%Cu-Ti-LowC,N based on the basic knowledge that fine ε-Cu particles are dispersed under high temperature deformation like thermal fatigue. This developed steel sheet had superior formability, high-temperature strength, thermal fatigue life, high-cycle fatigue life, oxidation and corrosion resistance and weldability. It showed the performance equivalent to SUS429 at 800°C or less, and compared to SUS429 it had a particularly superior r-value, deep drawability, salt and condensate corrosion resistance, and solidification crack sensitivity.
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  • Tomoya Yabu, Shigeto Yasuhara, Masakazu Kashiwagi
    2017 Volume 48 Issue 4 Pages 945-951
    Published: 2017
    Released on J-STAGE: June 25, 2019
    JOURNAL FREE ACCESS
    Through researching thermoplastic Glass Fiber Reinforced Plastic (GFRTP) crash box, we acquired knowledge to design front bumper beam system with load characteristic equal to metal structure. A GFRTP crash box is more efficient to absorb energy than steel one, so we can contribute to lightweight and small packaging of automobile. In this paper we show a development of crash box in front bumper beam made by woven fabric and random mat GFRTP with lightweight and high energy absorption. We paid our attention to compression load by ridgeline of crash box in progressive crash mode. Through researching structure and method of projecting load characteristic of GFRTP crash box, we propose a design method and confirm performance by a trolley test.
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Research Paper
  • Soichiro Watanabe, Masanori Harada
    2017 Volume 48 Issue 4 Pages 953-958
    Published: 2017
    Released on J-STAGE: June 25, 2019
    JOURNAL FREE ACCESS
    This paper investigates a real-time optimal control for an autonomous vehicle. The clock-based real-time optimal control that generates the so-called Carathéodory-π (C-π) trajectories has found wide applications in recent years due to an increase in computational performance. In this paper, the applicability of a propagation type Carathéodory-π (PC-π) controller for the vehicle lane change maneuver is investigated by numerical simulations using the full-vehicle model. Results demonstrate that the PC-π controller has the potential for the real-time optimal control of the conventional type vehicle.
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