The apparent activation energy of soot oxidation on a diesel particulate membrane filter (DPMF) was lower than on conventional DPF’s. The membrane layer of the DPMF, consisting of SiC nanoparticles. was covered by a silicon-oxycarbide layer containing single-nanosized Pt particles. In this study, the carbon black (CB) oxidation temperature with varying contact area between SiC nanoparticle and CB was evaluated. The CB oxidation temperature was observed to depend on the amount of oxygen adsorbed on the surface of the silicon-oxy-carbide layer. Moreover, CB was oxidized by adsorbed oxygen on the surface of the SiC nanoparticle. Pt increased oxygen adsorption.

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In the high gas velocity condition in cylinder, ignitability fluctuates by ground electrode orientation of spark plug due to gas flow condition change around spark gap. As one of the method to solve this issue, we have focused on the gas flow control by plate like airfoils or turbine blades. With this focus point mentioned above and adoption of current ground electrode welding technology, we have developed the gas flow control technology for spark plug to achieve high ignitability under worst condition of ground electrode orientation by locating the flow guide plate at plug housing.

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In order to elucidate the mechanism of low-speed pre-ignition (LSPI), a new visualization apparatus consisting of a test engine with optical windows and a camera trigger system was developed. The behavior of the spontaneous LSPI was compared with that of the LSPI reproduced by injecting deposit flakes into combustion chamber, and by making heavy knocking once to remove the deposits. From these experiments, it is likely that the deposit particles, peeling off from the combustion chamber and being heated to a high temperature by flame propagation of spark ignition before the LSPI cycle, are the ignition source of the LSPI.

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In this study, in-cylinder flow for a boosted GDI engine is investigated on an optical engine with a transparent sleeve using high speed PIV. A result of analysis of entire flow, a generated tumble flow in intake stroke is kept until the end of compression stroke. For investigation of turbulence, adequate time resolution is clarified and it is confirmed that cut-off frequency for a time filtering method is almost corresponded with a large time scale of flow, generated by piston motion. According to analysis, it is found that optimization of piston top shape is effective for enhancement of in-cylinder flow.

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In the use process of diesel particulate filter (DPF) an incombustible ash layer accumulates on DPF wall, and is the factor to reduce the particulate matter (PM) oxidation ability compared with the clean filter. Our aim is to determine an evaluation method of PM oxidation ability covered with a simulated ash layer. We composed a simulated ash layer using alumina powder that has suitability to PM oxidation ability of the DPF covered with a real ash layer and quantified the ability using a visualization system.

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Effect of a single lubricant oil droplet on gasoline-air mixture was investigated. Droplet diameter and temperature were changed as parameters by using an injector developed for this study. Test results showed that the ignition timing initiated by an oil droplet became early with decrease in droplet diameter or increase in droplet temperature. However, it was later than auto-ignition timing of gasoline-air mixture except some particular conditions. Heated oil droplet was required to initiate start of combustion followed by flame propagation.

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A feed-back control of fuel injection timing to reduce NOx and combustion noise during transition phase from diffusion combustion to Premixed Compression Ignition was attempted by utilizing maximum pressure increase rate (dP/dθmax) and 30% mass fraction burned (MFB) based on the pressure acquired by a glow plug with a cylinder pressure sensor. The outcome of this control was a great reduction in NOx and combustion noise.

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This study is to clarify the effect of the optimum compression and expansion ratio control on the thermal efficiency by variable valve timings with a single-cylinder heavy duty diesel engine equipped with external supercharging system. Test was done in various combinations of effective compression and expansion ratio with three different pistons having different geometric compression ratios from 18.0 to 26.0. The results showed that improvement in the gross indicated thermal efficiency by increasing effective expansion ratio was still significant with the highest compression ratio, while brake thermal efficiency was deteriorated by the steeply increased mechanical and pumping losses. On the other hand, it was confirmed that the excessive exhaust heat loss caused by the reduction in heat loss from the wall was able to transform into work by adjusting effective expansion ratio larger than fixed effective compression ratio.

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The PM oxidation behavior over ash-deposited catalyzed diesel particulate filters (CDPFs) was studied by using small-scale evaluation and visualization techniques. Before ash deposition, a CDPF with CeO₂–Ag (CA) catalyst reduced the temperature required for PM oxidation by about 100 °C compared to a CDPF with Pt/Al₂O₃ catalyst or to a DPF alone. The catalytic performance of the CDPF with CA was decreased by ash deposition, however, it was observed until ash deposition reached 40g/L by weight or 100 μm by thickness. ESR analysis suggested that this remote PM oxidation could be due to migration of superoxide species generated on the CA catalyst.

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This study aims at improving understanding of the relation between smoke-reduction effect of post injection and design and operating conditions in small diesel engines. A series of experiments was conducted using a single-cylinder diesel engine under a fixed NOx emission condition to investigate the smoke reduction effect of post injection varying the number of injection nozzle orifice and piston bowl diameter, which would influence the interaction between main spray flames and post sprays. The results indicate that the larger number of nozzle orifice with smaller diameter reduces smoke emissions under late post injection conditions. Advanced post injection reduces smoke emissions for the smaller piston bowl diameter; while retarded post injection reduces smoke emissions for the larger piston bowl diameter. Explanations for these trends were attempted paying attention to the influence of the main spray flames on post sprays.

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Motor operated clutch systems which do not need hydraulics enable these kinds of systems to contribute to higher fuel efficiencies and achieve superior shift performance. The targeted shift performance aims to achieve a natural torque transfer for the driver, meaning that fast and accurate clutch actuation in response to torque commands is required. Additionally, any system must be robust in a variety of environmental conditions. There are, however, many combinations of the different factors that lead to faster torque response, and in reality it is a challenge to find the optimum combination of these factors within the associated cost and layout constraints. In this paper we introduce the optimum combination of factors required for superior clutch torque response. These conditions were derived from simulations of multiple disc clutch pack force input responsiveness performed in the early design stages, along with the use of analytical models and quality engineering methodology.

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The brake for electric vehicles and hybrid electric vehicles requires suppression of deceleration variation by the cooperative brake control of friction brake and regenerative brake, which should not offer the driver discomfort feeling. We have developed electric servo brake system which control brake pressure using motor cylinder stroke. In this paper, the hydraulic pressure controller using motor cylinder stroke is described. By using the motor cylinder stroke, the controller fulfills servo performance and control stability under fluctuation characteristic of brake system. In addition, the controller realizes brake requirements for the case of emergency brake.

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The newly developed ThreeMotors Hybrid AWD system combines a V6 engine and transmission with a built-in motor, in addition to drive from two motors to freely control the allocation of torque between the left and right rear wheels. Concentrated windings were employed in the two motors in order to reduce their size. While these concentrated windings made it possible to reduce the size of the coil ends, vibration and noise became issues. Development focused on the basic framework of the motors and the form of the magnetic circuits that they employed. The utilization of magnetic circuits “Gradually enlarged air gap ” in which air gaps are gradually increased has reduced torque fluctuation and radial force and realized reduced size, increased power and efficiency, and quietness.

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This paper discusses the accuracy of the simultaneous state of charge (SOC) and parameter estimation method of the batteries for hybrid electric vehicles (HEVs) and electric vehicles (EVs) use. Although it is important to determine the battery aging, to control the charging and the discharging, and/or to maintain battery fault detections, the accuracy of the parameter estimation has not been thoroughly discussed. To address this issue, physico-chemical study using simultaneous state and log-normalized parameter estimation of batteries is provided in this paper. The proposed method is verified by performing a series of experiments using an EV.

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Recent years, the regulation of emission and fuel consumption have been becoming stricter. On the other hand, additional devices of engine make the engine control system more complicated. For these reasons engine control development load is becoming heavier and heavier. It is possible to improve efficiency of engine control development by making good use of models and development process where models are introduced is calledModel Based Development (MBD). But it is necessary to spend much time still and all at obtaining accurate engine plant models enough to apply them for control design. In this paper, rapid modeling process that includes sophisticated formula-based physical modeling methodology is introduced.

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To validate vibration test method of ISO 12405 for electric vehicles, we developed vibration test conditions, Power Spectrum Density (PSD) and test duration, using three electric vehicles under the assumption that these vehicles travel Japanese road. The PSDs were calculated from the chronological order data of acceleration obtained while running the vehicle according to each sub scenario. The developed test PSD indicated that the PSDs in ISO 12405 are validate. However, test duration of ISO 12405 for each axis doesn't validate, because calculated test duration for the X and Y axes in ISO 12405 are excessive, and for the Z axis is a bit short. Furthermore, in road environment other than Japan, the test durations of the X and Y axes does not exceed the test duration for the Z axis. Therefore, the test durations for the X and Y axes in ISO 12405 should be shorter than the test duration for the Z axis.

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In this study, we considered vibration reduction method using transfer function characteristics of operational TPA. Contribution was evaluated separately in each reference point, principal component, and transfer function of principal component. Countermeasure to the response signal was considered according to each characteristic. Floor vibration reduction of a model vehicle was performed to verify the efficiency. As a result, the vibration was reduced more with less additional weight comparing with a conventional method in which countermeasure was carried out focusing on only reference point signal. Consequently, the new method was found to be able to reduce the vibration more efficiency.

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A slight pitch difference is considered between the bolt and nut in this study. Here, the pitch of nut is α μm larger than the pitch of bolt. For four different levels of α , the loosening experiment is performed. Considering both the antiloosening ability and the clamping ability of the nut, the desirable range of α is discussed. Based on the loosening experimental results, several levels of α are selected in order to clarify the effect of the pitch difference on the fatigue life of bolt. The most desirable pitch difference is discussed in terms of improving both anti-loosening and fatigue life.

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Advanced Automatic Collision Notification (AACN) is a notification system that uses data about previous accidents to predict the extent of passenger injuries. The purpose of this study is to compare injury prediction models: the Honda-Nihon University model of Japan and the URGENCY model of the United States. These models are verified using 116 cases of Japanese in-depth accident data collected by the Nihon University and Chiba Hokusoh Hospital of the Nippon Medical School. Receiver operating characteristic (ROC) curves were generated by evaluating serious injury risks from the in-depth accident data, and the best models were selected to maximize the area under the curve (AUC) of ROC. In this result, the full model of the Honda-Nihon University model was the best model for predicting injuries during accidents in Japan, (AUC = 0.7699).

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The amount and rates of elderly fatally injured in traffic crashes in Japan are increasing. These tendencies are especially sensitive for thoracoabdominal injuries. In order to investigate this problem, a finite element model of an average size Japanese elderly with age-specific thoracic characteristics was developed. The thoracic response of the model was validated against age-dependent corridors developed from post mortem human subject pendulum impact tests. Full body trajectories and thoracic deformation were also assessed against frontal impact sled tests. The model shows good full body kinematics response as well as sensitivity to age-dependent characteristics.

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A liver Finite Element (FE) model with hyper-viscoelastic properties was developed. Hyper-elastic and rate-dependent characteristics were modeled with Ogden rubber material model. Such characteristics were validated against an original series of porcine exsanguinated livers under quasi-static and dynamic compression experiments. The applicability of the validated liver FE model was evaluated against a series of compression tests with porcine perfused livers to model nearly in vivo conditions. The regions where the FE model showed highest strain concentrations corresponded with the regions where perfused livers tested under dynamic loading sustained tissue damage. Based on this correspondence, ultimate strains for hepatic parenchyma and membrane were estimated by comparing strain patterns of the FE model with damaged conditions of the tested livers.

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We investigated the drivers' behavior in terms of avoiding collision or lane deviation, when equipped with multiple driving assistance system like Adaptive Cruise Control system (ACC) and Lane Keeping Assistance system (LKA). When we compare the driving behavior of using ACC and LKA with the driving of using single ACC, even though we observed the driver tends to carry out the secondary task like the operation of navigation system when following to a preceding vehicle, the possibility of rear-end collision was not increased. The driver also distributed attention to avoid collisions properly. Regarding the frequency of lane deviation, if we compare the driving behavior of using ACC and LKA with the driving of using single LKA, the frequency of lane deviation was even decreased. Many drivers reported that it was easy to concentrate on steering operation in using combined system. The driver seemed to be distributing his/her attention to several tasks adequately when equipped with ACC and LKA.

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This paper shows a technique for evaluation of the in-car device placement design. Bidirectional primary-secondary task method is introduced to evaluate both of the driving performance during the in-car device operation and the in-car device operation performance during the driving. While the operation performance is evaluated easily based on the success rate of the device operation and so on, the driving performance is evaluated based on the index of the decision making ability of the driver. This index is quantified as the entropy by utilizing the Probability weighted ARX model. The position of the operating device is evaluated in the proposed evaluation framework. Primary task is the vehicle following task and the secondary task is the panel touching task. Driving data are collected on a driving simulator and a mathematical model of driving behavior is identified using each set of data. By calculating the model entropy of PrARX models and the success rate of the device operation, one can evaluate the influence of each device operation on the driver’s decision-making ability in a quantitative manner.

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It is well known that three dimensional motion of a rigid body can be described by a rotation about a fixed axis. Also, force and moment applied to a rigid body can be regard as a force along a line of action. The motions of the pelvis and the thorax, steering forces and torques of a driver on two different seats are visualized by instantaneous screw axis and line of action respectively. The screw axis of the thorax passes close to the center of mass of the head. Relative screw axis between thorax and pelvis goes through the center of mass of the upper body in both cases. The line of action regarding the steering force reaches the driver’s shoulder girdle when driving on the seat that has larger back support. The proposed method can be helpful to consideration of the driver’s motion from a mechanical view.

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The steering entropy (SE) method has been proposed as an index for quantifying driving workload when performing a secondary task while driving. However, this method has certain limitations, including an inability to measure driver workload in real time. This presentation describes a newly developed real-time steering entropy (RSE) method, which improves the conventional SE method by incorporating a real-time measurement capability, and presents an evaluation of its practical utility. The results revealed that the RSE method can accurately detect various conditions in which the driver encounters high workload on driving.

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Predicting temperature variations of vehicle parts by CFD is considered an effective tool to reduce vehicle development time. But existing methods are difficult to be applied to the advanced development of vehicles due to long computing time or low accuracy. In this study, we developed an efficient approach to predict parts temperature variations based on weak coupled method. This method boasts high calculation accuracy almost comparable the Strong Coupled Method (SCM) by using a new interpolation technique, while the calculation speed is several ten times higher than SCM.

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We manufactured an exhaust heat recovery heat exchanger prototype which was a small and simple structure of offset fins installed on a double tube. The prototype was compared with a mass-produced model in tests of heat transfer and pressure drop performance by using hot air and a coolant. As the results, the prototype showed a heat recovery capacity of more than 800 W, the overall heat transfer coefficient for the prototype exceeded that for the mass-produced model for a Reynolds number of less than 1500 and the slope of the curve for the prototype was smaller than that for the mass-produced model. Therefore, the prototype is considered to be more suitable for small gasoline engine cars to enhance the heating capacity of an automobile cabin than the mass-produced model because a bypass valve and a bypass pipe may not be needed with the prototype due to the heat transfer features mentioned above.

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The engine exhaust particle number emission bigger than 23 nm is regulated using a solid particle number measurement system established by Particle Measurement Programme (PMP) in Europe. The emission of solid particles below 23 nm also attracts attention, because the existence of sub-23 nm solid particles in engine exhaust was reported. Special care should be taken to prevent losses of such small particles and re-nucleation of volatile fraction. A hot catalytic stripper was applied to a PMP system. The capability for sub-23 nm particle measurement of the system was investigated evaluating characteristics of particle counters and volatile particle removers.

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The inspection of heavy duty vehicles using a portable emission measurement system (PEMS) in Europe and America has some problems, which requires a commercial vehicle to be modified for installing PEMS and kept from business for a certain period of time. Because of these problems, in Japan, the introduction of heavy duty vehicle inspection using PEMS is difficult. In this paper, we introduced sensor-based emission measurement system (SEMS) that can capture signals from the NOx sensor, and the CAN of the intake air amount and the fuel injection, and transmit them to digital tachograph. The NOx emission and fuel consumption were calculated from the measurement data of the SEMS, and then we examined the effectiveness of SEMS by comparing those results with those of PEMS.

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This study aimed to analyze effective driving way and change to eco-driving using the eco-driving pilot program data. The data of nineteen participants who drive regularly the same route were selected for the analysis with the view to exclusion of the fuel economy influencing factor except for eco-driving. Sixteen of nineteen (84%) had improvement effects from 5.6 % to 36.8%. The contributions of idle and the other driving status were different in individuals. The results of analysis indicated that the driving changes of idling stop before and after moving, and gas pedal off early were main factors of fuel reduction.

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Restrictions on automotive CO₂ emissions, representing the basis of global standards for fuel efficiency, are increasing in severity throughout the world. Today, composite materials of plastic and fiber are used in several tens of thousands of automobile bodies per year. High expectations are held for fiber-reinforced plastics (FRP) due to their light weight. The research clarified a mechanism making it possible to stabilize loads produced in response to compressive input, in addition to examining a method of minimizing the effect of temperature.

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We have developed a new tire surface-profile inspection system that has the following two features: Firstly, the “Tire KANAGATA (die) Model” can be used to adjust the variation of data statistically. Secondly, the interactive interface for human inspectors with the inspection system is introduced for the efficient and flexible construction of the “Tire KANAGATA (die) Model” for newly designed tires. Using these features, the usability of the auto-inspection system is improved, with no oversight, minimum over-detection, and efficiency for teaching set-up.

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