Exhaust emissions and combustion stability of diesel engines can be improved by feedback control using a cylinder pressure sensor (CPS). However output of the CPS can deteriorate due to deposits on the sensor. To address this issue, an on-board model was developed to compensate CPS output based on the spring-mass-damper model. Young's modulus of the deposit causes a variation of the spring constant and resulting degradation of the signal level. Deposit porosity leads to a variation of the damper constant and resulting signal delay. The proposed model based on the analysis can estimate the cylinder pressure with the required accuracy for the feedback control.

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A simple on-board model was proposed to compensate CPS (cylinder pressure sensor) output based on the springmass- damper model in the previous paper. In this paper, compensation capability of the proposed model was evaluated with several engine tests following investigations of deposit characteristics with a nanoindenter and a micro-focus X-ray computed tomography system. The results showed that a spring constant of the model was proved to be related to sensor dispersion, an attenuation coefficient was proved to be related to a detecting speed of the pressure sensor. The proposed model well compensated effects of the deposit clogging by identifying these constants during motoring state.

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Dynamic cylinder deactivation or dynamic skip fire (DSF) has shown significant fuel economy improvements via reduction of pumping losses that generally affect throttled spark-ignition engines. Lean burn gasoline engines also promise significant improvements in fuel efficiency through reduced pumping losses and enhanced thermodynamic properties. However, stratified lean engines suffer from higher particle number emissions and cannot tolerate high charge motion levels desirable for homogeneous lean and stoichiometric operation. This article introduces a new concept that integrates dynamic skip fire with homogeneous lean burn, which extends high efficiency homogeneous lean operation to low loads, resulting in fuel consumption benefits of 4.3 – 9.2 % depending on the cycle (NEDC, WLTP, JC08, HWFET).

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A calculate method of mass burnt fraction (MBF) using ignition plug washer type force sensor was investigated. The correlation of MBF 50% crank angle and low order frequency component that measured by ignition plug washer type force sensor is high. Similarly, correlation from start of combustion to end of combustion has been confirmed by this method. In this result, estimation of MBF history was possible.

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In this paper, an engine combustion control scheme based on ASPR based adaptive output feedback control via Todai-Discrete model for diesel engine with triple fuel injections will be evaluated through simulations. The effectiveness of the engine combustion adaptive control with an appropriate feedforward control will be confirmed through numerical simulations for a specified driving model.

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The purpose of this study is to elucidate the seizure mechanism of the polymer overlay sliding bearing material. Five kinds of wear tests from running-in to seizure were performed and wear surfaces of the bearings were observed with an SEM/EDX and laser microscope in detail. As a result, the base material of aluminum alloy has been exposed by abrasive wear and shear fracture of the overlay and/or the interface between aluminum alloy and overlay. And the seizure occurs when temperature rapidly rises due to adhesion between shaft material and aluminum alloy.

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Suppression of heat transfer in internal combustion engines has become a critical issue for improving its thermal efficiency. Heat insulation by a wall material which has low heat capacity and heat conductivity is one of the effective ways to reduce wall heat flux. In this study, it was focused on comparing the effect of heat insulation on heat transfer coefficient between compression and expansion stroke. As a result, reduction rate of heat transfer coefficient during expansion stroke was higher than that in compression stroke. It was due to increase in reduction rate of turbulent kinetic energy in wall boundary layer.

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Prediction of ignition timing through model-based control on ECU (on-board) is essential to improve the transient performance of diesel engines. In the previous studies, the authors developed an on-board polytropic index prediction model for compression stroke that was solely applicable under steady conditions. In the present study, newly developed models were added to improve prediction of the polytropic index for compression stroke under transient driving conditions. The average and maximum errors of polytropic index under transient conditions compared to the result of 1-D engine simulation were 0.37% and 1.06%, respectively. Additionally, the calculation time of the model per cycle was 50.6 μs, sufficient for on-board calculation.

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In-cylinder total gas sampling technique has been developed by using hydraulic variable valve actuation system. PM (Particulate Matter) included in the sample gas was trapped on quartz filter, and PAHs (Poly-Aromatic Hydrocarbon) components and soot were quantified by TD-GC / MS (Thermal Desorption Gas Chromatograph Mass Spectrometry) and carbon analyzers, respectively. Cylinder-averaged histories during / after combustion were obtained by changing the sampling timing. PM formation processes were analyzed by using this technique.

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Diesel surrogate model consisting of four hydrocarbon fuel species has been applied to engine CFD simulation. In addition to the fuel oxidation reaction, poly-aromatic hydrocarbons (PAHs) formation mechanisms were also implemented into the model, which allows simulating soot precursor production. Soot was calculated from PAH by using method of moment model implemented in CFD code CONVERGE. In-cylinder PAHs and soot formation processes were validated by comparing with the experimental results of the 1st report.

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To improve thermal efficiency of engine，the requirement forWaste Heat Recovery (WHR) system is increasing．Rankine cycle is the most promising system for WHR，because it is practical and high efficiency in small temperature difference．In this paper，development of compact and high efficiencyWHR system with a new cooling system using latent heat are investigated．The system showed a remarkable fuel consumption improvement over the wide operation range of a passenger car engine．

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In the first report, engine experiments using a single-cylinder diesel engine found that GTL-emulsion fuel drastically reduced NOx and smoke emissions, while also improving fuel efficiency, and visualization of the spray combustion process in a constant volume chamber showed GTL-emulsion fuel achieves a soot-less flame even in diffusive combustion. In the second report, effects of injection pressure and water content ratio on soot formation process were clarified by combusting spray visualization. It is found that as water content ratio of GTL emulsion fuels are increased, the averaged intensities are drastically reduced, and attain zero level at the 24% water content for the various injection pressures.

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In the previous research, it became possible to avoid abnormal combustion at high load by using gasoline high pressure injection and showed the possibility of high compression ratio. In this paper, we tried to make the concentration of the mixture in the combustion chamber homogeneous for the purpose of further improving efficiency at low speed full load. By using CAE to analyze and improve the mixture state, we achieved thermal efficiency over conventional engine.

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An enhancement of a tumble flow is one of the effective methods to improve lean and diluted combustion stability limits in SI engines. In this study, an evaluation method of the tumble flow quality by means of multipoint LDV is proposed. Effects of a tumble flow quality to turbulent characteristics and flame propagations are also investigated. Tumble ratio, turbulent intensity, effective opening areas and tumble qualities which are defined as standardized targets of phenomena to develop in-cylinder flow of SI engine. It is shown that the standardized flow characteristics targets make possible to improve the thermal efficiency and stabilities of lean and diluted combustion limits.

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In the roll skyhook control, undesirable vibration amplification occurs due to the time lag and phase delay of feedback controller. In order to suppress the influence of the undesirable roll vibration, we used the wheelbase filtering that causes frequency at which roll oscillation is minimal. Hence, we appropriately designed control signal filters considering roll-lateral coupled motions and conducted an experiment with an actual vehicle to confirm performance benefit.

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Statistical Energy Analysis (SEA) is an effective tool for the analysis of noise and vibration problems on tires. This paper discusses the applicability of Analytical SEA, which uses coupling loss factors (CLF) evaluated theoretically. At first, the CLFs of three kinds of tire are experimentally evaluated and it is shown that the frequency characteristics are classified into three frequency ranges. Next the analytically estimated CLFs are compared with the experimental results for establishing the analytical formulation in Analytical SEA. It is concluded that the Analytical SEA modelling in low frequency ranges below about 200Hz can be established.

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In Japan, the pedestrian occupies the most fatalities of traffic accidents. The characteristic of a pedestrian fatal accident is that the majority of cases occur during crossing. In the conventional pedestrian detection, only the pedestrian in front of the own car is detected. Therefore, the detection is suddenly and the reaction is difficult. This paper proposes the detection method which has a margin of time by detecting intention and danger of crossing before a pedestrian cross the roadway. Proposed method adopts Deep Neural Network as the machine learning method used for pedestrian detection, and the results of the different input data form are compared. This paper shows the details of the proposed method and the results of application to videos of the drive recorder.

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In recently, almost freighting in Japan is supported by truckload transportation. So, trucks are important commercial vehicles for logistics. Therefore, it is situated as important subjects, protecting occupants from collisions. Trucks, registered in land transportation office of belong to Japanese Land and Transportation Ministry, are classified 3 types, as heavy duty trucks, medium duty trucks and light duty trucks. In medium duty trucks, there are included truck-type as operation permissioned by driver license for semi- medium class vehicles. Therefore, 18 years old persons are able to driver license for this class trucks. So, medium duty trucks are expected to become main type trucks for freight transportation in the future. In the previous study, the author clarified drivers' injury contents of collisions between heavy duty trucks from viewpoint of statistical analysis by using traffic accident integrated data stored in ITARDA (Institute for Traffic Accident Research and Data Analysis). In the present study, the author applied the analysis method, by using traffic accident integrated data, for analysis of drivers' injury in collisions between medium duty trucks, and it is clarified detailed occupants' injury speciation by body regions.

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For the reduction of minor neck injuries during rear-end impacts, an advanced dynamic test method using BioRID-II dummy has been discussed for the UN ECE/WP29/GRSP/GTR No.7. This study was focused on some certification tests for BioRID-II dummy in order to reduce differences in the responses of dummies used in dynamic tests. Specifically, the certification tests proposed by the dummy manufacturer were carried out for the jackets and pelvises of BioRID-II dummies to examine the validity of the existing dummy performance requirements of those certification tests.

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Merging task is one of complex tasks at the highway junction or interchange. The merging car should be controled taking account not only with the safery condition but also with the drivers driving on main lane to realize a harmonization among all related drivers and ADAS systems. In previous research, authors presented the decision making modeling of the driver driving on main lane to estimate if he/she accepts the merging. This study proposes the realtime prediction method of the acceptance state of the main lane drivers by using model predictive control framework based on the obtained model.

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Sense of self-agency (perceived control) has been proposed in psychology field and means “I am the initiator or source of the action”. In this study, psychological experiments using a simple driving simulator were conducted focusing on how operator’s sense of self-agency changes corresponding to a degree of assistance against a disturbed operation environment. The result showed that sense of self-agency was maintained when the degree was moderate, whereas the sense was decreased when the degree of assistance was high. It suggested that an automated system can be categorized based on the degree of assistance.

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While a driver is driving on the highway by using Level 2 Automated Driving System, a system failure occurs, and the main constituent of the driving operation changes from the system to a driver. In this situation, necessary margin of time for a driver to take over manual operation is examined from the experiments conducted for normal drivers by using a driving simulator.

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The authors have developed a new numerical analysis method based on Euler-Lagrange Coupling to clarify the soot deposition phenomenon on Exhaust Gas Recirculation (referred to as EGR) cooler for diesel engines. Cooled EGR system with a heat exchanger (EGR cooler) for diesel engines has been used for emission improvement for a long time. Since diesel engines tend to generate much soot, however, the performance of the EGR cooler is likely to decrease due to the deposited soot. The flow of EGR gas is computed by Eulerian method and the soot particles are simulated due to Lagrangian approach. Because this new analysis is combined the merits of each method, the present authors call this procedure as Multiphysics simulation. The trajectory of soot particles was analyzed and the situation of accumulation by thermophoretic force was clarified. Then changes in heat transfer due to deposited soot were compared in various fin shapes. The authors found that the thermophoretic force and the generation of longitudinal vortices are important for reasonably simulating the soot deposition phenomenon.

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To design EV/PHEV battery air cooling system efficiently, a CFD approach to predict battery temperature variations is developed. In this approach, computation time can be greatly shortened by using steady analysis to calculate the fluid field. And the calculation accuracy is also secured by considering the effects of the temperature variations and distribution of cooling air and batteries in detail. Finally, the accuracy and practicality of this method are also confirmed by comparing results of strong coupling analysis and the battery bench test.

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For the practical aerodynamic performance enhancement of the vehicle, the grasp of the on-road turbulent wind environment is required. Therefor the wind turbulence measurement car which could drive in the public road was prepared for. Furthermore, for a purpose to grasp the characteristic of the on-road wind turbulence, the relation between the road environment and the characteristic of the wind turbulence were analyzed.

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Application of tapered handlebars using high strength aluminum alloys is effective to weight reduction and high texture appearance. However, due to the influence of Cu contained as a strengthening element, the extrusion productivity of material pipe was low, and the cost was high. Therefore, an alloy in which the addition amount of Cu was suppressed and which was strengthened by addition of Zn was selected. In addition, stress corrosion cracking resistance was secured by optimizing manufacturing conditions. As a result, the weight was reduced by 20% and the cost was reduced by 30%．

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Many automobile frame parts are constructed by joining hat parts to each other, so it is very important to clarify the deformation behavior of hat-shaped parts during vehicle collision. In this study, the effects of a part shape and load input conditions on axial crush deformation behavior of double hat parts were investigated. As a result, it was found that the double hat parts composed of hat parts of the same shape show a stable axial collapse deformation behavior regardless of the load input condition. On the other hand, it was found that the deformation behavior different from the above is exhibited in the double hat parts composed of hat parts with different forming depths. If the collision load is first input to the hat part on the deep side of the forming depth, it became clear that the hat parts are deformed so as to separate from each other during the axial pressure collapse, and the absorbed energy is remarkably lowered. Furthermore, it was clarified that the separation mode will be suppressed by disposing a connecting plate so that the hat portion straddles the inside of the hat portion under the condition of generating this separation mode.

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The microstructure in welded joint affects the residual stress. Therefore, accurate phase transformation behavior is necessary to predict residual stress by numerical simulation. Moreover, the phase transformation in the resistance spot welded joints is caused during rapid heating. However, non-isothermal transformation behavior in resistance spot welding were not clarified. In this study, phase transformation behavior in resistance spot welding were measured by using optical fiber thermometer for the purpose of the accurate prediction of the residual stress.

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The first report showed the correlation between the meteorological environment and the temperature environment inside the exposed vehicle in Okinawa, and proposed a method for estimating the temperature inside the vehicle from the meteorological data by using the relation Ci in the invehicle environment specific heat. In this second report, meteorological data from arbitrary areas other than Okinawa were used to increase the versatility of the method for estimating the temperature inside the exposed vehicle. The enhanced in-vehicle environmental specific heat Ci was determined to be unique to the vehicle and not to change depending on the area. The Ci value calculated from a short-term exposure test can be expanded to the in-vehicle temperature history of a one-year exposure test that is not actually performed. In addition, the yearly in-vehicle temperature history can be estimated from the yearly weather data in any area of the world without actually performing an exposure test in that area. By estimating the in-vehicle temperature history from the meteorological data of various areas around the world, the base in-vehicle temperature history can be obtained for selecting the accelerated deterioration test conditions.

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This paper proposes a method to evaluate whether constructed map contains enough amount and precision of landmark information for autonomous driving. The proposed method uses only the map information itself to judge the capability of autonomous driving and therefore the method does not need any trials of autonomous driving control nor simulation, which leads to reduction of time and cost for map evaluation. Firstly, this paper generates the map for autonomous driving using lane-marker positions detected by on-board cameras. Secondly, the generated maps are separated with a certain length of sections and the proposed map evaluation method is applied at every section of the map. The method uses statistical analytics algorithm based on Simple Linear Regression Model, which determines whether the amount and deviation of landmarks (lane-marker positions) assures lateral distance position error of less than 0.5 m. Effectiveness of the proposed method is verified using manual driving data on a test course.

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This research is intended to clarify the technical requirements of the Automated Driving System which is highly acceptable for many drivers. The system for the research can utilize vehicle-to-pedestrian (V2P) and vehicle-to-vehicle (V2V) communication system in order to detect surrounding pedestrians and other vehicles which are not seen by the driver. And also it can reduce the risks of collision by not only supplying information or warning to the driver but also controlling the vehicle speed. The technical requirements are studied through the experimental test result by utilizing the driving simulator.

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