The history of study on stability limit control of gasoline engine was so long and many of them controlled the past cycle combustion fluctuation rate. However, most of the cycles are less than the stable limit fluctuation rate even when the engine is operated near the stable limit. Therefore, if the future cycle fluctuation rate can be predicted, it is considered it becomes possible to extend the lean limit. So, we investigated the specifications of the partial Autocorrelation of IMEP fluctuations. This result showed that the former cycle had significant influence on the next cycle and the proportion of the alternating fluctuations was high. This report shows the method and performance which predicts adaptively the next cycle IMEP fluctuation rate based on the above results.

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A high compression ratio is effective for improving the thermal efficiency of internal combustion engines, but the problem is controlling knocking. Previous studies have shown that NO / NO₂ present in EGR affects autoignition, but the mechanism is not fully understood. In this study, kinetics of elementary reactions between NO₂ and fuel-derived intermediate products were investigated based on chemical kinetics.

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Using the valve train as the subject material for this research, a method was created for rapidly realizing optimization through a high-level reconciliation of conflicting relationships between numerous functions and systems that had formerly presented issues in the time required for verification. Multi-objective design exploration, which clarifies relationships among multiple requirement items necessary for a design and determines their design range, was used for this research. As this approach significantly reduced the period of time for determining specifications compared to conventional development, it is reported herein.

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In this work, the ash mobility was modeled to estimate the ash distribution in Diesel Particulate Filter channels and the pressure drop throughthe filter. The characteristics of accumulated ash, i.e. particle diameter, porosity, and permeability were taken into account to model the transport.The model was finally validated with experimental data of DPG (Diesel Particulate Generator). As a result, predicted ash distribution in thechannel and pressure drop through the DPF have good agreements with measured data by the use of DPG.

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We focused on low-temperature emissions and aimed at reduction by Air-fuel ratio (hereafter, A/F) control. Feedback control immediately after starting is required to reduce emissions, and for that purpose it is important to be able to control the A/F sensor even at extremely low temperatures. To meet this demand, we have developed a new A/F sensor that has a waterrepellent function and has significantly enhanced water resistance. It was confirmed that not only water resistance but also responsiveness and output performance are compatible. As a result, we confirmed that the vehicle has the potential to reduce emissions at 25°C by 20% and in the -7°C environment by as much as 50% compared with conventional vehicles.

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In this study, NH₃ oxidation reaction over a hydrothermally aged Cu–CHA-type SCR catalyst was studied and a model for prediction of the rate constant of the NH₃ oxidation reaction over hydrothermally aged catalyst was constructed. The results show different trends of temperature dependence on the NH₃ oxidation reaction rate above 300 ℃ for catalysts with different aging time. The structural analysis of the aged catalyst revealed that the Cu²⁺ and H⁺ active sites primarily were affected by aging and, thus, the NH₃ oxidation reaction rate at relatively lower temperatures can be determined from the number of the active sites. In contrast, the amount of CuO and the number of Cu²⁺ and H⁺ active sites can be used to determine the NH₃ oxidation reaction rate at higher temperatures.

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To quantify the difference of ordinary drive steering response performance by measurement data is one of an issue that OEMs have faced difficulty for a long time. In particular, slight difference in vehicle behavior induced by body reinforcement is widely known by recent studies ^(1-4). In this study, we tried to identify vehicle behavior signals to quantify such effect as “vehicle behavior felt by drivers”. In order to extract the effect of “vehicle behavior felt by drivers” with and without body reinforcement objectively, we analyzed a large amount of measured time-series data using machine learning and deep learning.

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Vehicle dynamic model is normally constructed using tire forces such as cornering forces and camber thrusts. Since these forces are functions of the sideslip angle and camber angle, it is impossible to perform continuous analysis from the stopping condition to high-speed driving in the model construction. Therefore, it is necessary to construct different tire model to describe tire characteristics between stopping condition and ordinary speeds. However, in the motion of a two-wheeled vehicle, especially, there is a problem for standing stability at a stopping situation or at an extremely low speed. In this research, in order to solve these problems and apply it to two-wheeled vehicle dynamics, we construct a new tire model that can be applied from stop to high speed driving.

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This paper presents a design method for continuous fiber variable axial composites in three-dimensional space with locally varying orientation distribution under multi-loading conditions. The design method is formulated based on topology optimization by augmented tensor field design variables. An adaptive weighted sum method is formulated to fulfill design requirements. The fabrication method of designed structure is planned by Tailored Fiber Placement technology, whereby the preform is prepared by a CNC embroidery machine. The optimized composite design achieved comparable performance as the baseline aluminum frame with 15 % weight reduction.

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In the authors’ previous researches, it is found that the bolt nut connections having pitch difference can realize both fatigue life improvement and anti-loosening performance successfully. The most desirable pitch difference for improving the fatigue life is relatively smaller than the most suitable pitch difference for improving anti-loosening performance. In this paper, the effect of the nut height on the tightening and untightening of the pitch difference nut is investigated experimentally and analytically. It is found that the suitable pitch difference range for anti-loosening can be reduced with increasing the nut height. Therefore, the larger nut height may realize both anti-loosening performance and high fatigue strength.

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This article describes some effects of visual messages in a vehicle to inform drivers of operational design domain（ODD） in conditionally automated driving. A driving simulator experiment（DS） was conducted to measure drivers' responses to an event in which conditionally automated driving ended outside ODD with a long enough time margin of 15 sec for them to cope with the Taking-Over Request（TOR） situation. Five visual messages, “Figure only（no text）”, “Please Take-Over”, “Highway Exit” , “Automated Drive OFF”, and “Automated Drive OFF/ Please Take-over” were designed to investigate their effects on drivers’ responses to the TOR situation in this study. Thirty drivers participated in this experiment. They were asked to perform a non-driving task while automated driving was active. The results of the DS experiment showed that when either “Figure only” or “Highway Exit” was issued, drivers did not stop being more engaged in the non-driving task and there were larger lateral displacements of the vehicle. The human machine interface in a vehicle was discussed in terms of adequate visual messages to inform drivers of the ODD in conditionally automated driving.

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When the driver fails to respond to a request to intervene issued by a level 3 automated vehicle, the system considers a way to reduce the risk by performing a system operation called minimum risk maneuver (MRM). In this paper, a driving simulator experiment investigates the effects of MRM conditions such as hazard lamp activation, amount of deceleration, and stop position on vehicles approaching from the rear under different traffic conditions. As a result of the experiment, effective MRM conditions for reducing the risk of collision with a vehicle approaching from the rear are clarified, and we propose them as MRM considerations.

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In order to develop an algorithm of distraction warning for heavy-duty truck drivers, a subjective evaluation of forward careless state which should have to be warned in case of distraction, was conducted with a various driving behavior clipped scenes. Then, an estimation algorithm for forward careless state to be warned was devised, based on the face orientation/position, recognized by Driver Monitoring System (DMS). The algorithm was implemented on the DMS embedded in the A pillar of the cabin, and evaluated on an actual traffic road. As a result, it was confirmed that this newly developed algorithm consists a good capability of detecting various types of distraction properly.

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For the purpose of reducing traffic accidents and improving traffic convenience, the research and development of the automated driving and advanced driver assistance system is in progress. For more future, we think additional values such as comfort and economy in these systems will be more demanded. In this paper, we propose an integrated speed planning control method that mediates multiple speed plans based on the scene judgment for the real driving environment. And we show that proposed method is effective using the verification results which simulated the actual driving environment.

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We carried out bending analyses of thin-shell square cylinders using finite element method (FEM) to investigate the effective width. The accuracy of Karman's formula and Noma's formula were verified in the case of 270-1500 MPa materials. Furthermore, we proposed a new high precision formula based on these FEM results. The new formula improves the efficiency of a car body design. In addition, a strength and a stress distribution were verified in the case of the member has a hole. In general, the hole reduces a strength of a structure. In this study, we clarified a condition to detoxify the effect of a hole using burring.

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In the application of high strength steels to energy-absorbing parts of automobile, it is important to stably obtain high absorption energy by suppressing fracture in crash deformation. In this study, a new fracture resistance evaluation method simulating the axial crashing deformation in the press formed area was used to clarify the effects of mechanical properties and microstructure on the fracture behavior. High hole expansion ratio (λ) steel with tempered martensite and bainite suppressed both initiation and propagation of the crack in the pre-formed area. From these results, the fracture resistance was thought to improve by controlling microstructure for high λ.

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In autonomous driving, there is a relationship between path planning and motion control. The former should be based on the feasibility of vehicle motion, and the latter requires real-time calculation including path planning. Therefore, simultaneous optimization of path planning and control, called SPPMC (Simultaneous Path Planning and Motion Control), is important. In driving in the real traffic environment, decision making has also strong interaction with plannnig and control. In our research, we realized and simulated Decison making and SPPMC for lane-change with speed / steering angle control by nonlinear MPC (Model Predictive Control).

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This study presents servo system design that simultaneously achieves vibration suppression and desired reciprocal motion of a wiper system. First, linear dynamics of a wiper system is derived based on theMaxwell’s frictional model. Next, a modal analysis is conducted to select modes to be controlled and derive reduced-order dynamics, which enables to provide smaller controller gains for improving safety and satisfying the voltage limitation of automotive batteries. A new servo system is presented, in which not only output reference but also desired signals of all states are assigned to significantly improve the tracking performance of reciprocal motion.

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A millimeter-wave radar is expected for autonomous driving and ADAS since it is less affected by weather and illumination conditions. However, it is difficult for the radar to precisely recognize shapes of the objects due to the low spatial resolution and noise. We dare to challenge reconstruction of the parking scene where they are required. Classes and shapes of various objects in the parking lot and street parking were estimated. We designed our original deep neural network and showed that it can be estimated with high accuracy. It was confirmed that ours is superior to the typical conventional networks.

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Probabilistic explanation of system reliability will be required due to autonomous driving. I had studied accurate design including deviations in recognition of around vehicles. If the distribution is obtained from the result of the numerical operation of the big data, the probability accuracy may be deteriorated. To obtain accurate results, it is necessary to create distributions for each parameter and obtain the target distribution by distribution calculation. I propose accurate design determining the control risk associated with the driving control from recognition data.

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A multicomponent fuel model, which estimates the gas-liquid equilibrium and property values of the fuel mixture, can represent the fuel concentration distribution characteristics of each component of a multicomponent fuel spray. In this paper, the WAVE-MTAB model is applied to a breakup model in order to simulate the spray characteristics of a twocomponent fuel spray under high pressure injection pressure conditions. As a result, the two-component spraying behavior and the fuel concentration distribution of each component in a multicomponent fuel spray under high pressure injection conditions could be reproduced in comparison with the experimental results.

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The deep learning model we developed estimates knocking sound pressure and knocking component superimposed on in-cylinder pressure from engine radiation noise captured by a microphone. This model obtains time frequency mask and frequency response from many pair data of engine radiation noise and in-cylinder pressure. The time frequency mask extracts the knocking sound from engine radiation noise. The frequency response converts the extracted knocking sound into the knocking component superimposed on in-cylinder pressure. We propose a knocking detection method using this model and verify this method at wide range of engine operating conditions

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The current control of HV engine starting vibration suppresses the drive train vibration by controlling two motor generators(MG) individually， and their parameters are tuned using prototype vehicle. In this paper, to realize the model-based development without prototype, a cooperative control model of two MGs for whole system vibration was constructed, and a new control which can improve the control effect was developed.

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The Cooling loss characteristics of FC (fuel cell) system are: (1) Thermal energy produced by FC stack is mainly dissipated to the coolant. (2) The energy efficiency variation with respect to the power variation is large at high load or high temperature compared to the ordinary use range. (3) The allowable temperature of FC stack is low compared to ICE (internal combustion engine). The radiator tends to be large to keep FC stack temperature moderate from these characteristics. The purpose of this study is to redress the balance between the cooling capacity and cooling loss, by implementing the control of the FC power output focused on the characteristic of (2).

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This paper proposes a dual-motor electric vehicle (EV) drive system with a dog brake for changing the drive mode. A conventional dual-motor EV drive system is not capable of regeneration or reverse drive in single-motor mode because of overrun in the sprag-type one-way braking system. In this study, a new dog-brake system was developed in order to expand the operating region. This allows changing from single-motor mode to dual-motor mode operation without a reduction in vehicle driving force. In addition, the brake can be disengaged simultaneously with starting of the motor. We prototyped the new dual-motor EV drive system and evaluated its basic performance. It was confirmed that the dog brake allows the drive mode to be changed without a reduction in driving force. Moreover, the oscillation of the longitudinal acceleration was the same as that for vehicle with a conventional dual-motor EV drive system.

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This study deals with the standing stability of two-wheeled vehicles at standing still situation and at extremely low speed. Most of the studies on vehicle behavior for two-wheeled vehicles are studying for characteristics beyond medium speed and analyzes on extremely low speed and stopped state characteristics have hardly been performed. Standing stability at extremely low speeds for a two-wheeled vehicle is one of the major problems for ordinary riders. In this research, first, a simple model for a human body is constructed using the hitch point on the waist as a connecting point between the upper body and the lower body. This model is incorporated into the equation of motion of a motorcycle at stopping condition, and its outline is grasped. In particular, the influence of each design parameter on standing stability is shown.

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A Multi-material structural members for Automobile which absorb the crash energy by deforming in the automotive body collision were developed by sandwiching a small amount of resin between an ultra-high strength steel structural parts and a resin fixing plate made of a thin steel. When this structure was applied to 1470MPa grade steel parts, the fracture of the parts was avoided, and the energy absorption in the axial direction was improved over 50%, and the weight was reduced by 25% in comparison with the parts of the same performance.

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This paper describes a methodology to design vehicle body frames in the early stage of product development considering the target weight range. 2D maps were generated to show the relationship between the body frame layout, weight, and performance such as crashworthiness. A combination of parametric modeling and machine learning enabled to identify candidate solutions with various parameters and their ranges before making drawings.

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In this study, we investigated an influence of vehicle interior noise and steering vibration on the vehicle speed recognition performance and the comfortableness in cabin for the compatibility. In the subjective evaluation test, the speed recognition performance and the comfortableness were evaluated using a driving simulator when various frequency or level increasing sound or vibration was presented. As the result, the frequency increasing sound especially at low frequency band was found to increase the speed recognition performance without deteriorating the comfortability. In addition, the steering vibration change was also found to be a cue to recognize the vehicle speed.

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Accidents in which elderly people make the mistake of stepping on the accelerator and brake have become a social problem in Japan. This study examined the relationship between human factor indicators and the occurrence of stepping errors in the elderly. In a mock-up experiment, we conducted an analysis of variance between the stepping error rate and human factor indices for accelerating while teaching the brake. The analysis showed that the walking ability assessed by the two-step test, which constitutes the Locomotive Syndrome Tests, and the attentional function assessed by the TMT Part B were significant.

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As vehicle electrification progresses, physical spaces inside instrumental panel for a defroster nozzle become narrower and nozzle sizes are required to reduced. Under such constraint conditions, it is important to design a defroster nozzle, satisfying requirements of windshield defrosting-demisting performance with low costs. In this paper, a reduced order model (ROM) is developed to predict instantly windshield velocity distribution, namely windshield defrosting-demisting performance. An inverse design method utilizing decision tree algorithm and ROM is established to find out instantly design conditions of defroster nozzle that fulfill performance requirements. Effectiveness of the method is validated by CFD performance results of a small defroster nozzle derived from the method results.

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Ammonia (NH3) measurement method using a potentiostatic sensor was developed. NH3 emitted from a gasoline vehicle in WLTC mode was measured using the suggested method and was compared with that measured using a near-IR laser based NH3 measurement system and FTIR. It was found that the NH3 signal obtained from the method was qualitatively in agreement with those obtained from the other measurement systems. The factors leading to the difference between the NH3 concentration in exhaust measured by our new method and those measured by FTIR or laser absorption spectrometer were also investigated.

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In order to apply high tensile strength steels to the energy absorbing parts, the problem is the destabilization of the energy absorbing property due to the fracture in crash deformation. In this research, orthogonally reverse bending (ORB) fracture test is proposed to evaluate fracture behavior in axial crash deformation with consideration of press forming process. Axial crash tests and ORB fracture tests are curried out for various materials of 980 MPa class, including Dual Phase and Transformation-induced plasticity steels to clarify the mechanism of crash behavior. The experimental results shows that the ORB fracture test is able to simulate the axial crash fracture of press formed parts.

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In Japan, the issue is how to prepare for a power outage in the event of a disaster, and it is expected that the 100V-AC power outlet installed in an electric vehicle will be utilized. However, since there are not many quantitative surveys on actual usage, we conducted a questionnaire survey using the case of the Hokkaido Eastern Iburi Earthquake and found that about 70% of the owners of the vehicles were able to utilize the in-vehicle 100V-AC power outlet.

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New vehicle regulations with regards to Automated Driving Systems were adopted by World Forum for Harmonization of Vehicle Regulations (WP.29) on 24th of June 2020. The cyber security regulation(1) by WP29 had been one of the prioritized items in the frame work document for these new regulations. This regulation does not define specific requirements to qualify security measures implemented in vehicles. Whereas, this regulation defines processes by vehicle manufactures for cyber security in place. The paper will outline the regulation as aspects of its feature, requirement and application for vehicle type approval.

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