Some of injected fuel form liquid film on the internal wall of intake port or cylinder and will evaporate in later cycles. In order to achieve an optimal air-fuel ratio control at cold-start cycles, a quantitative, transient fuel liquefying and evaporating progress has to be estimated. In this study we have developed the method to calculate the amount of fuel-film at each cycle bymeasurement of transient intake air flow and transient concentration of exhaust gas component (CO, CO2, and THC).With this method we have made a statistical model which can estimate the mass of fuel-film at any condition. Then we practically applied the model to the feed-forward injection control to keep stoichiometric air-fuel ratio at cold-start cycles.

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This study introduces super lean burn engine with over lambda 2.5 that achieves both high thermal efficiency and significantly low NOx emission. Key technologies for combustion such as ignition, flame propagation, and unburned HC reduction are described firstly, and then the possibility of further improvement of thermal efficiency and combustion effect by applying ethanol as carbon neutral fuel to the super lean burn engine is indicated.

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Methane (CH₄) is one of the main constituents of the exhaust gas emitted by compressed natural gas (CNG) vehicles. CH4 has 25 times higher greenhouse effect than CO₂. Furthermore, it is difficult to be purified by a three-way catalyst (TWC) because of its chemical stability. In this study we clarified that lean / rich lambda oscillation improves CH₄ purification by contribution of oxygen storage capacity (OSC) of TWC. In addition, we investigated the mechanism of CH4 purification improvement by in situ FT-IR analysis.

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Ammonia is attracting attention as a decarbonized fuel due to no CO₂ emission, easily liquefaction and relatively high efficiency for storage and transport. The reciprocating engine with an on-board reforming system to extract highly combustible hydrogen from a part of ammonia has been developed, because ammonia has low combustibility. Feasibility of the ammonia mono-fueled engine was studied for cold-start, securing of operational range and emission control.

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An industrial reciprocating engine was added the developed on-board reforming system, because ammonia has poor combustibility. Usual operating range of the engine system was kept by co-firing hydrogen reformed partially from ammonia. The developed engine system was modified to be mounted on a towing tractor and a power generator as demonstration machines. The evaluation results indicate that the engine can be used equivalently as existing internal combustion engines using fossil fuels.

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This study demonstrates the cold start performance of an ammonia mono-fueled engine system. The system was composed with a commercial four-cylinder spark ignition engine and a developed on-board ammonia reformer by means of autothermal reforming. A TWC (three-way catalyst) and a SCR (Selective Catalytic Reduction) catalyst were also adapted the system for exhaust aftertreatment. The ATR reformer provided stable hydrogen within several seconds with supplying electrically preheated ammonia-air mixture. The engine achieved a starting operation in 3 seconds after the starter turned on although the first combustion took place under relatively low hydrogen fraction. Zero ammonia emissions and pretty low NOx and N2O emissions were obtained during cold start following idling condition by controlling the mixture excess air ratio depending on each aftertreatment catalyst conditions. The adsorbed ammonia on the SCR passing through the TWC before its activation was oxidated by SCR reaction under lean operation.

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Recovering the waste heat is important to improve fuel efficiency of a hybrid electric vehicle. In this study, waste heat recovery systems such as organic Rankine cycles (ORC) and thermoelectric generators (TEG) were applied to a series hybrid electric vehicle with a lean burn SI engine that can be operated at an excess air ratio of 2.0. The effects of waste heat recovery systems on fuel economy were evaluated by using one-dimensional numerical simulation. The improvement of fuel economy using ORC and TEG was 2.67% and 1.14%, respectively. ORC was more effective in improving fuel economy than the TEG.

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To estimate piston skirt friction loss precisely, it is important to comprehend the influence of piston design parameters on the oil supply mechanism. This study aims to clear the influence of piston motion on piston friction and oil supply mechanism. Piston friction and oil film on piston skirt was evaluated by floating liner method and induced fluorescence method. And piston motion was measured by gap sensors installed on piston skirt. This study found piston motion affect friction loss. And it was suggested the location of sliding area on a piston skirt has significant impact on the amount of oil supply.

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Improving the energy balance of electric vehicles (battery electric vehicles and hydrogen fuel cell electric vehicles) is one of the major issues for their widespread use. In this paper, we propose a mechanism that appropriately utilizes the coasting state that allows the vehicle to move far away without using any energy. The mechanism is not a gear shift to the neutral range but an accelerator pedal operation support. For the purpose of reducing unnecessary accelerator pedal work, we have experimentally verified the enhancement of functionality that gives vibration feedback to driver of a vehicle according to the position of the accelerator pedal and traction battery power.

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In this study, hydrogen embrittlement of a new stainless steel, STH2, with reduced amounts of Ni and Mo has been examined with respect to the effects of tungsten inert gas (TIG) welding and cold rolling technologies. Tensile tests at -40℃ were conducted for specimens containing around 30 ppm hydrogen precharged by exposure in 10 MPa hydrogen gas at 300℃ after TIG welding and 20% cold rolling. Slow strain rate tensile (SSRT) properties were evaluated in high pressure hydrogen gas up to 70 MPa at -40℃ after 70% cold rolling. At -40℃, no significant elongation drop due to hydrogen charging was observed, and about 100% of relative elongation of specimens heat-treated in air with the same heat pattern was obtained. Elongation of 70% cold-rolled sheets increased with increasing hydrogen gas pressure up to 70 MPa more than in a 0.1 MPa N2 atmosphere. It was confirmed that STH2 even when subjected to TIG welding and cold rolling has excellent properties not only with respect to internal hydrogen of around 30 ppm but also in high pressure hydrogen gas.

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Vehicle Neutral characteristic is one of the most important performances of Vehicle Dynamics. By expanding the area of thinking of the phenomenon to extremely low frequency vibration, we succeeded in quantitatively expressing this characteristic, which has not been quantitatively explained in the past. And by focusing on the phenomenon, we explain the mechanism of this characteristic. Then, it turns out that the cause of extremely low frequency vibration is airflow, we developed items that improve its aerodynamic characteristics in principle. The vehicle that weaved the items has confirmed that there are Vehicle Neutral characteristics with extremely low frequency vibration reduction.

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TM Tire Model (Tread Mechanics Tire Model) presented in the previous research improved the approximation accuracy of the cornering stiffness by devising the model of the tread part. This model tends to provide high approximation accuracy, especially for tires with low profile and wide (High-Performance Tire). Therefore, we considered the mechanism that increases the approximation accuracy, and investigated and verified the effect of tire tread specifications on cornering s stiffness. As a result, we were able to clarify part of the mechanism from the viewpoint of shape of contact patch and deformation against load.

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We are developing an oscillation suppression control method to reduce resonance caused by torsion of driveshafts. It is desirable to apply a control method that is easy to understand and has high performance within the range of classical control theory. In this paper, we have developed an oscillation suppression control method based on the difference between motor rotation speed and tire rotation speed, which only has one feedback gain to be tuned. The tire rotation speed is estimated by an identity observer that takes torsion into account, characterized by changing the values of matrices depending on whether the tire is gripping or slipping. The effectiveness of the proposed method has been verified by simulation and driving test.

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The need for ride comfort design that takes into account the coupling of suspension/tires and drive train is increasing due to changes in rotational inertia and stiffness of the drive train caused by the electrification of the vehicle. In this paper, it’s confirmed that the dynamic model of the suspension/tire and the drivetrain inertia / stiffness can reproduce the actual phenomenon. Also a ride comfort design method that combines the resonance and anti-resonance of the suspension/tire and the drivetrain is proposed.

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From the perspective of ensuring road traffic safety for next-generation vehicles, it is important to create a database of actual road friction characteristics. We have proposed a new method that enables continuous measurement and have shown the measurement results for different road surfaces and measurement conditions. Based on these results, this paper shows that the advantage of this continuous measurement is that it can measure the characteristics of road surfaces with variable friction properties and obtain measurement results that depend on the measurement location. We also show the quantitative validation results of this device by correlating the measured results with the provided road friction characteristics in wet conditions. Next, we show the differences in the properties of road surfaces with different coefficients of friction due to different road surface conditions, such as dry and wet conditions, and show that the range of decrease in properties due to wetting varies greatly depending on the pavement condition and other factors.

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In this paper, trade-off study technique between vehicle body in white mass and stiffness is proposed by using multi-objective design exploration algorithm. After sampling analysis for the part thickness, surrogate models were created by machine learning technique. Pareto front was specified by use of the surrogate model, and the specifications of the Pareto solution enabled countermeasure study to achieve the target between vehicle body in white mass and stiffness.

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The characteristics of force transfer in the wheel significantly affects the vehicle controllability. In this study, thin-film sensor was developed and mounted on a brake rotor, which achieves dynamic measurement of surface pressure on the wheel hub during real driving. It was cleared that the slight difference in the stiffness distribution of the wheel affected the response of the hub surface pressure.

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This paper analyzes the mechanism of vibrational energy propagation and panel vibration generation at the point joints between frame and panel which can be applied to reduce the noise. First, it is shown that the transmitted power at point joints that contribute to the panel vibration is caused by the out-of-plane component in relation to the frame deformation, and the evaluation of the out-of-plane transmitted power makes it possible to identify the effective site for reducing the panel vibration. Next, the relationship between the energy inflow to the panel and the panel vibration during the initial propagation of the traveling wave was numerically verified, and a panel vibration reduction method was proposed by suppressing the energy propagation to the panel．

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This paper focused on the effects of non-acoustic factors on community response, namely annoyance and activity disturbances due to road traffic noise. Most of previous surveys in Japan addressed community response to noise for detached houses rather than that for apartments. However, it is likely that the above-mentioned community response differed by sound insulation performance between detached houses and apartments. Using a social survey conducted in areas facing arterial roads in 2019 and 2020, we applied the micro data to cross-tabulation and logistic regression analysis. Calculating phi coefficient and odds ratio, we discussed the difference by housing types.

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In this paper, an evaluation method for in-cylinder pressure oscillation is developed to quantitatively determine the magnitude of combustion noise in the 7-10 kHz band characteristic of pre-chamber jet combustion engines. In this method, in-cylinder pressure is measured for 400 cycles of crank angle history, and peak-to-peak amplitudes of pressure oscillations in the combustion chamber resonance band are obtained for cycleby- cycle using a bandpass filter. The peak-to-peak amplitudes are then averaged to obtain an evaluation indicator for in-cylinder pressure oscillation that enables an indirect evaluation of high-frequency combustion noise without measuring engine radiation noise. The results showed that the evaluation indicator in pre-chamber jet combustion is 16 times higher than that of conventional spark-ignited combustion, which can be evaluated at a single fixed in-cylinder pressure sensor.

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For motorcycle users, sound such as engine sound is essential one of the attractive issues, and there is a tendency to demand a certain volume. However, an increase in the generated sound volume is undesired social issue, because it increases environmental load at the same time. As a solution to this contradictory matter, we introduce a method that has realized both road traffic noise reduction and enriched sound presentation to rider. This method is by vehicle exterior structure.

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To discuss the causes of pedal misapplication accidents, we analyzed primary party drivers’ number of pedal misapplication accidents in the past decade using the Japan Traffic Accident General Database. We examined the relationship between factors such as road types and driving movements and compared them between elderly and non-elderly drivers. When the effects of traffic exposure were offset by using the number of secondary parties in rear-end collisions, it was confirmed that elderly drivers over the age of 75 were particularly more likely to be involved in pedal misapplication accidents relative to their traffic exposure.

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Cooperative recognition has been proposed as a method for human-automation cooperation in autonomous driving. In cooperative recognition, when assigning tasks to operators (i.e., request intervention), it is necessary to consider not only driving safety and efficiency but also human capabilities. In this study, we optimize the intervention request planning by formulating the problem with a Partially Observable Markov Decision Process. We evaluated the proposed method with a simple simulation to discuss the validity of the method and obtained the implications for future development.

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Reduction in the running resistance of an automobile, especially, that in the aerodynamic drag, is important for realizing carbon neutrality. However, a vehicle with low aerodynamic drag is known to have poor crosswind stability against the yaw-angle variation of the incoming flow. Sound understanding of the unsteady aerodynamic characteristic is crucial to ensure the steering stability in crosswind conditions. In this study, the unsteady flow around the vehicles subjected to yaw-angle fluctuation of incoming flow is investigated by Large Eddy Simulation, with a particular emphasis placed on the phase delay in the fluctuations in the surface pressure and those in the resulting side force acting on the vehicle.

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To prevent extreme climate events, it is urgent to reduce greenhouse gas emissions, and research on alternative fuels for internal combustion engines is necessary. In this study, diesel spray and combustion characteristics were investigated when Fatty Acid Methyl Ester (FAME) was blended with Hydrotreated Vegetable Oil (HVO) in any ratio. As a result, blending HVO with FAME promoted atomization and improved evaporation, resulting in a lean mixture. Also, the shorter ignition delay suppressed premixing combustion, resulting in lower cylinder temperatures and lower NOx emissions, but increased THC and Smoke emissions.

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A diesel particulate filter (DPF) model that can be incorporated with whole vehicle model to simulate a transient driving condition was developed using OpenModelica software. A particle oxidation process in the model is expressed as a simplified single step reaction, and occur even in the situation that a regeneration is not appeared. Regeneration properties observed with a DPF diesel passenger car was reproduced with the model. According to the results with the passenger car model, an appropriate regeneration control, which terminates the regeneration at the point where soot remains to some extent, will improve the fuel economy.

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Aiming to realize a decarbonized society, gasoline vehicles will be abolished by the middle of 2030 and converted to electric vehicles. On the other hand, the ratio of electric vehicles to passenger cars in Japan is less than 1%. There is almost no driving record data of electric vehicles for long-term. The driving record of electric vehicle, Nissan LEAF, for 12 years from 2011 to 2022 was compiled and evaluated on the characteristics of electric vehicles. The seasonal variation of electric consumption from the driving records was observed, so that the correlation between electric consumption and temperature was confirmed.

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It is essential to clarify the contribution of air conditioning to the CO₂ emissions of vehicles in terms of real-world fuel economy. SAE J2766 is used as a method for this purpose, but the heating conditions of BEVs have not yet been supported. Therefore, in this study, a new method was developed to quantify CO₂ emissions of all powertrains by heating tests using actual vehicles. In addition, CO₂ emissions from air conditioner use in 2035 were then estimated for each region and a proposal was compiled.

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Moisture swing adsorption, which controls the adsorption and desorption of CO₂ through the water content of adsorbents, is a novel method for direct air capture. In this study, to clarify the adequate management of adsorbents with cross-link, we investigated the effect of adsorbent water content on the CO₂ adsorption capacity. Additionally, the effect of water quality, which is used for the desorption process, was investigated. Results showed that the adsorption capacity increases when the adsorbent slightly contains water. Moreover, we clarified that nitrate and sulfate ion concentrations equivalent to river do not reduce the adsorption capacity.

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This study aims to evaluate the impact of cooperative automated driving vehicles equipped with CACC (= Cooperative Adaptive Cruise Control) on the traffic flow of regular roads. The impact of CACC vehicles on traffic flow was analyzed in terms of two points: the effect of maintaining a short distance between vehicles, and the effect of reducing reaction delays. The spatial redistribution effect by maintaining a short distance of CACC vehicle can be expected, on the other hand, it showed the possibility that sufficient effect could not be demonstrated in the low-speed range. In the analysis of the reaction delay, it is found that CACC vehicles in front of the queue at signals can contribute to the traffic congestion reduction effect. Furthermore, a traffic simulation of the traffic congestion reduction effect network-wide experimented with the data set of the Mitaka-Kichijoji model. In the result, it was shown that a certain effect of CACC vehicles could be obtained for the overall traffic condition (total delay) by the rate of 50% or more of CACC vehicles.

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In order to predict the wear characteristics of Al-Sn-Si alloys used in automotive sliding bearings, it is necessary to understand the transitionprocess of wear mode and its mechanism under lubrication. In this paper, the wear tests were carried out varying sliding speed and load underlubrication with additives, and the wear and seizure mechanisms are discussed. As a result, seizure does not occur with the additive lubricant andtribo-film is formed on the wear surface. In addition, detachment of the tribo-film was observed when the load was increased. Based on theseresults. we proposed a new wear progression process for Al-Sn-Si alloys under lubricating with additives.

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In order to significantly reduce CO2 emissions from automobiles, it is essential to develop technologies for improving the thermal efficiency of internal combustion engines, such as lean combustion, and fuel technologies suitable for combustion. In this study, the effects of fuel composition on lean-burn engines were verified, and by analyzing the effects, fuel characteristics that achieve both knock suppression and lean-burn limit expansion were investigated.

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Effect of pilot fuel injection on graphitic crystallite size and oxidation reactivity of soot particles from a small DI diesel engine was investigated experimentally. The soot particles were sampled from exhaust gas, and its graphitic crystallite size was investigated by laser Raman spectroscopy and high-resolution transmission electron microscopy (HRTEM). Oxidation reactivity of soot was evaluated by thermalgravimetric analyzer (TG). The graphitic crystallite size of soot increases with increasing the pilot fuel injection quantity. The results of TG analysis indicated that the oxidation reactivity of soot decreases with the increase of graphitic crystallite size.

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In a spark ignition engine，the setting of ignition timing is an important factor for thermal efficiency and engine power．In this study，a prediction model for the knock limit ignition timing was developed by combining the 0-dimensional calculation inside the engine cylinder and the statistical model．It was confirmed that the model showed good agreement when the in-cylinder state related to combustion was changed such as􀀃 intake air amount，intake valve timing or external EGR rate with wide range.

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LII measurement was performed to investigate the soot formation process in a region where diesel spray flames impinge onto the wall and adjacent these flames interact with each other. It was carried out using an optical accessible RCEM with a two-hole injector. Effects of injection pressure and ambient oxygen concentration was discussed．It was found that high concentrations of soot were formed in the interaction region, soot was formed in a wider range and remained for a long time when reducing the injection pressure, and soot was formed even when increasing the oxygen concentration, but it is reduced earlier.

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The effects of fuel components on EGR and lean limits in multi-cylinder gasoline engines were investigated. The combustion stabilities for various fuel components varying the olefin contents and adding oxygenate components such as ethanol and ETBE were especially evaluated. The experimental results show that the fuel components have a significant impact for the EGR and lean limits. It was found that the fuel containing a large volume of olefin with ethanol could extend not only EGR and lean limit but also knock limit. We revealed the potentiality for improving thermal efficiency with adjusting fuel components.

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For improvement of diesel combustion efficiency, in-cylinder air injection was attempted. Air injector was installed near fuel injection nozzle on a single cylinder diesel engine. The effects of air injection duration and timing on the diesel combustion performance were investigated. Compared with the conventional diesel combustion, air injection case showed higher peak of heat release rate, improvement of indicated work and reduction of the smoke emission. These results suggest that air injection near the fuel injection nozzle can improve the combustion performance by promoting air entrainment into the diesel spray flame.

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To realize a super-leanburn SI engine with a very-high compression ratio, it is required to design a new fuel which could have low ignitability at a low temperature for antiknocking, but high ignitability at a high temperature for stable combustion. Ethane shows a long ignition delay time at a low temperature close to that of methane, but a short ignition delay time at a high temperature close to that of gasoline, as well as having a higher laminar burning velocity than those of methane and gasoline. In the present study, the antiknocking effect of adding methane with the RON of 120 or ethane with the RON of 108 to a regular gasoline surrogate fuel with the RON of 90.8 has been investigated. Adding methane or ethane by 35 % or 25 % in heat fraction, respectively, shows the same knock limit SI timing as that of a premium gasoline surrogate fuel with the RON of 100.2. In the relationship between the heat fraction of the gaseous fuel and the advance of knock limit CA50, the effect of adding ethane is 1.9 times larger than that of adding methane. The effect of adding the gaseous fuel is dependent not on the RON of the gaseous fuel, but on the OH consuming rate of the gaseous fuel. The effect of adding methane or ethane to the premium gasoline surrogate fuel has been also investigated. The effect of adding ethane is 1.7 times larger than that of adding methane. The effect of adding the gaseous fuel is not dependent on whether the liquid fuel has cool-flame reactions or not.

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In order to ensure the safety and long-term reliability of automotive batteries, it is essential to understand the response of lithium-ion batteries against large-scale deformation, such as nail penetration and crush tests, as well as steady charge-discharge cycling accompanying with heat generation and deformation. Therefore, it will be quite useful for battery safety and reliability design if those phenomena can be predicted by simulation. In this study, a battery model was constructed that can reproduce the charge-discharge characteristics of automotive lithium-ion batteries based on the deep and precise understandings of the compositions, and their thermophysical and mechanical properties, and the model was improved by contrasting with the experimental results of heat generation and deformation behavior during charge-discharge. The temperature inside the battery and the swelling phenomena during charging and discharging was estimated using the model constructed in this study.

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Radio waves are managed in the world that frequencies can be used effectively and mainly in telecommunications, which are a limited resource. Since Wireless Power Transfer (WPT) transmits power in the air using electromagnetic fields, a WPT system interference with telecommunications equipment and other devices. This report investigates the electromagnetic environmental effects of the DWPT system. Two types of electromagnetic field evaluations were conducted to ensure that the system does not affect other electrical equipment (Electro-Magnetic Compatibility: EMC), and the human body (Electro-Magnetic Force: EMF). The results of the EMC evaluation indicate to keep the EMC limits even when 50 kW of power is transmitted per vehicle. The maximum value of EMF estimates within the EMF reference even when 25 kW of power is transmitted per coil by placing near a wheel.

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A body frame of a battery electric vehicle (BEV) and the structure around the battery case require high collision safety performance and the protection of the battery. In this study, for BEV battery protection, we focused on a steel energy absorption (EA) member with a wave structure mounted inside the sidesill. The study clearly shows that the EA efficiency of the member was affected by both of the buckling behavior which varied with the shape and thickness of the member, and the material strength. In particular, the EA efficiency is increased significantly with the increase of a material strength when the amount of the out-of-plane deformation decreased.

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In the present study, we propose a data-driven set-based design method employing Differential Evolution Based Adaptive Sampling (DEBAS) and explore its application to the Multi-disciplinary Design Optimization (MDO) problem of battery cell straight hat-shaped busbar. Busbars, responsible for electrically interconnecting the multitude of cells in an electric vehicle's battery pack, primarily demand electrothermal performance during energization, assembly performance in the manufacturing welding process, and mechanical strength as key performance attributes, each quantified through respective Computer Aided Engineering (CAE) techniques. A busbar shape that can simultaneously satisfy multiple performance criteria and be integrated into a component unit, known as a busbar module, has been successfully developed.

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In all regions of vehicle motion where forward and lateral acceleration occur simultaneously, several mechanisms that front/rear driving force distribution affects cornering characteristics are analyzed. By considering the tire SAT characteristics in combined slip and the differential friction, it has been clear that the effects of driving force distribution can be divided into five regions in the GG diagram. It has been shown that larger driving force distribution to the front wheels leads to weak understeer in some regions.

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The study described in this paper aim to further enhance the estimation accuracy of the suspension stroke velocity using the vertical acceleration sensor on the sprung mass. Previous studies have confirmed the effectiveness of including the nonlinear characteristics and delays of semi-active damper in the observer model. However, the observer could not estimate correctly near unsprung resonance point. To solve this problem, we try to use LSTM to estimate the stroke velocity. The effectiveness is verified by carrying out simulations and experiments.

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Tire lateral forces play the most important role in determining vehicle motion performance. In this paper, we considered the generation mechanism of lateral force and applied a novel driving force control law that simulates lateral force. As a result, we were able to confirm a wide range of improvements in dynamic performance, such as steering responsiveness and disturbance stability of the vehicle, as well as contributing to eliminate unnecessary forces that cancel out each other between diagonal wheels.

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This paper compares the characteristics of in-cylinder pressure measured in actual engines for various combustion modes and the characteristics of flame distribution and fuel reaction rate due to flame propagation calculated by CFD for those same modes, based on previous research. Results show that the significant increase in high-frequency in-cylinder pressure oscillation in pre-chamber jet combustion is due to two factors: a high in-cylinder pressure rise rate that is 2 to 3 times higher than in conventional spark ignition combustion, and an asymmetrical flame distribution caused by differences in fuel reaction rate of jet flames ejected from multiple nozzles of the pre-chamber.

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One of the challenging issues in V2X system to help prevent Car-to-Bicyclist crashes is the information reliability, to be more specific, for the cases where cars do not encounter bicyclists owing to their sudden direction change (false positive) or for those where cars encounter bicyclists with no signal transmission (true negative). Car drivers’ acceptance was investigated to understand the influence of the extent of false positive and that of true negative. To reduce adverse effect by highly relying on receiving the information, an extra investigation aiming to maintain driving attention by offering the fundamental traffic circumstance risk was performed.

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This paper proposes a new method for analyzing the impact performance of vehicle bodies in the early stages of design. The method is called Impact Statistical Energy Analysis (ISEA), which is based on the propagation of energy and considers the conversion of kinetic energy of the structure into internal energy in the deformed parts of the structure during a crash. The paper discusses the effectiveness of ISEA in comparison with damper mass models and FEM models for one- and two-member structures.

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Predictions using machine learning typically require a large number of design variables that contain performance results (aerodynamics, crash, etc.). Proposed technique based on VAE (Variational Autoencoder) can generate new styling by sampling from latent space values. This method was applied to an engine hood outer. The FE mesh was created by VAE and its eigenvalues were analyzed. The results matched well with the results of created from CAD. It was suggested that machine learning improved prediction accuracy.

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We considered the test method of Real Driving Emissions (RDE) for heavy-duty vehicle. In the last report, we proposed Model BasedTesting (MBT) approach, which combinates HILS (Hardware In the Loop Simulation) and engine bench system, which is calledExtended-HILS. In this second report, we constructed the MBT method of RDE, which is called RDE-HILS. This HILS program has Vehiclemodel, Driver model and Virtual Road model, which is reproduced the real road conditions of straight road, curved road and road gradient. Weestimated the emissions from commercial truck and RDE-HILS and verified the RDE of heavy-duty vehicle by using this MBT approach.

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