CO₂ capture from engine exhaust using the adsorption method was investigated. Engine exhaust emissions and a representative gas consisting of only air and CO₂ were used as the test gasses. A four-stroke gasoline engine and 4.65 kg of zeolite 13X, which was held in a canister with an internal volume of 6.5 L, were used to conduct the tests. The results showed an approximate capture rate of 90% CO₂ at 30 minutes after introducing the representative gas. With the engine exhaust gas, CO₂ was also selectively captured by the zeolite, even when H₂O, CO, and THC coexisted with the CO₂.

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The visualization experiments of fuel film attached on the cylinder liner associated with post-injection were conducted by applying the photochromic visualization technique to the optical diesel engine under motoring operation. It was confirmed that the thickness of the lubricating oil film became extremely thin at the area where the fuel impacted with post-injection, while the fuel oil film became thicker. It was also confirmed that the fuel oil film on the liner was scraped by the top ring and moved to the piston land.

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In this study, the active control of reductant pulse supply was investigated using the SCR reaction model to improve the NOx purification ratio and reduce the amount of reductant supply in a urea-SCR catalyst system. The improvement was obtained when the active control of amplitude and frequency of NH₃ pulse supply was carried out at low temperature. In this case, it was important to increase the ammonia coverage while suppressing the formation of ammonium nitrate.

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In this study, the active control of reductant pulse supply was investigated using the SCR reaction model to improve the NOx purification ratio and reduce the amount of reductant supply in a urea-SCR catalyst system. The reduction of NH₃ slip was obtained when the active control of amplitude and frequency of NH₃ pulse supply was carried out at low temperature. Moreover, low NH₃/NOx ratio had roles in not only reducing extra NH₃ supply amount but also keeping high NOx conversion ratio by the improvement of NOx conversion by suppressing the formation of ammonium nitrate.

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The purpose of this study is to investigate the effect of spray-spray interaction on the entrainment mechanism in diesel combustion field. In this paper, the ambient air flow is measured with laser induced fluorescence and particle image velocimetry (LIF-PIV), and the backflow arrival distance is used to understand the ambient air flow. The interaction region between sprays is estimated from the geometric relationship of the sprays in the multi hole nozzle case, and the indicator of influence by the spray-spray interaction on the entrainment mechanism is proposed. The correlation between the experimentally measured backflow arrival distance and the theoretically calculated degree of the influence by spray-spray interaction on the entrainment mechanism was investigated, and the effectiveness was evaluated.

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In this study, the spray behavior of direct injection gasoline engines is analyzed under low temperature conditions. DISI engines have a problem of the emission characteristics during cold start. Fuel injection is closely related to PM/PN. The purpose of this study is to understand the spray behavior under low temperature conditions. The experimental equipment to control the fuel temperature and the wall temperature was constructed assuming low temperature condition up to -20°C (253K). The characteristics of free spray and wall impingement spray were measured and analyzed. As the fuel temperature decreased, the spray tip penetration increased by 4.7 % at a fuel temperature of 273 K and by 8.4 % at fuel temperature of 253 K compared to 293 K. The spray angle decreased by 6.4 % at 273 K compared to 293 K, and by 14 % at 253 K. In the case of the wall impingement spray, maximum impingement spray spread distance was suppressed by the change in wall temperature, but the effect of the ambient temperature was also considered.

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It has been reported that gasoline direct injection (GDI) vehicles are widely used in the world including Japan. Different from traditional port fuel injection (PFI) of gasoline vehicles, they emit considerably more particulate matter (PM). Then, the filtration system for gasoline soot is needed, called a gasoline particulate filter (GPF). In this study, we conducted a numerical simulation of flow field and soot filtration in GPF with straight flow, corresponding to the flow parallel to the filter wall. First, we simulated the flow field in a two-dimensional domain. Secondary, we conducted three-dimensional simulation of soot filtration by using the boundary condition of the flow field in 2D simulation. In the simulation, we changed the length of the filter wall to keep the velocity normal to the filter wall. Based on our results, we discussed the effect of straight flow on the soot filtration.

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Motorcycle frame flexibilities greatly affect the straight running stability. Conventionally, the effects of these have been analyzed using a mathematical model in which multiple frame flexibilities are combined. In this paper, it is proposed that a method for analyzing the effect of a single frame flexibility (5 degrees of freedom model) on straight running stability from a composite frame flexibility model (10 degrees of freedom model). Specifically, it is described that the influence of individual frame flexibility can be estimated using the one based on the analysis model in which all the frame stiffness values in the 10- degree-of-freedom model are extremely large.

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The steering response characteristics, robustness, and disturbance toughness when a yaw moment proportional to the yaw rate was applied to the vehicle (feedback control) and when a yaw moment corresponding to the steering angle speed was applied to the vehicle (feedforward control) were compared and examined. By combining feedback control and feedforward control, steering response characteristics equivalent to those of a vehicle with a yaw moment of inertia halved can be obtained, and robustness and disturbance toughness are improved. These relationships can be said to be the basic principle of DYC control in the transient state.

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In automobile industry, the welding is usually employed to connect metal and metal parts. However, recently, adhesives with large internal damping are used to join structures instead of welding. Therefore, we formulate the sensitivity of subsystem energy to internal loss factor in SEA. We considered the perturbation of the loss factor in the SEA fundamental power balance equation. We can deduce a guideline for reducing the subsystem energy by adding the damping to appropriate subsystem. The guideline is shown that the damping addition is more effective on the subsystem in the path from the excitation subsystem to the response subsystem.

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In this study, computational simulations were performed for investigating suppression of buckling thin wall square tube with compressive and bending condition. In order to realize ideal deformation mode, a method for constraining buckling of each plane was developed. Results of constrained buckling plane combination showed that suppressing buckling of compressive plane is the most effective for retaining force and buckling of side wall is simultaneously constrained.

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We evaluate influence of error factors on occupant posture behavior in pre-crash by experimental design method. By using a sled model for car crash analysis with a seat and a virtual human model considering a muscle tone, effects of error factors such as seat position, seatback angle, and vehicle behavior on occupant posture changes are analyzed. In addition, we investigate influence of error factors on injury risk of occupant posture by frontal impact analysis.

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Ensuring collision safety is an important issue in automobile body design as well as weight reduction. As a material supplier, we propose applying lightweight materials such as high-tensile steel and aluminum alloys to vehicle bodies. And this time, we have set up a unique full-scale collision safety evaluation facility for evaluating the proposed materials, structure, and joining method. The outline of the equipment and a part of the measurement technology are introduced.

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Hands-off function of driver assistance system is expected to have an effect on driver’s workload reduction of cognition, judgement and operation. In this study, compared with hands-on condition, the effectiveness of the hands-off function was examined through a field test of highway driving. As a result, driver’s subjective fatigue and effort, heart rate variability as an index for mental workload, and muscular activity of upper limb as an index for physical workload showed lower level in the hands-off condition. The hands-off function was thought to be effective on the workload reduction. Furthermore, structure of fatigue was clarified through factor analysis.

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In this study, we conducted a psychological experiment to identify the driving patterns of road rage that occurs from the following vehicle using a driving simulator. In the experiments, we divided the participants into experienced and inexperienced drivers to compare vehicle distance and degree of risk for normal driving versus backward-attentive driving (i.e., driving while paying attention to the vehicle to one’s rear) when perceiving road rage. The experimental results show that inexperienced drivers perceive shorter vehicle distances during normal driving than they do when engaging in backward-attentive driving. However, there was no changes in perception of vehicle distance for experienced drivers, and stable driving behavior was observed. These results suggest that experienced drivers maintain stable driving, and more readily avoid road rage.

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In this study, we investigated the effect of modality when providing videos during automated driving on the driver's takeover performance in the transition from automated driving to manual driving. In the basic experiment, participants were requested to perform video viewing task and visual detection task during automated driving. Significantly, the reaction time was about one second longer for pay more attention to video viewing than for pay more attention to outside. In the verification experiment, we evaluated the effect of interface modality of video viewing on participant’s performance when avoiding a collision with a front obstacle just after providing a takeover request (TOR). Significantly, TTC (Time to Collision) was shorter for video viewing without audio than for video viewing with audio.

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The 38-item Workload Sensitivity Questionnaire (WSQ38) was originally designed for general drivers. In this study, we attempted to create a shortened version for senior drivers. As a result of analysis using latent rank theory, we were able to classify the items into three groups of ranks according to the degree of subjective workload. A shortened form was proposed and validated using the top items with the highest item discriminancy. It became clear that about 10 to 9 items were sufficient to measure the degree of driving workload (WSQ9 or WSQ10).

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Visual workload while driving is increasing because of the growing amount of information presented to the driver by a high-functioning onboard unit. A method of HMI to intuitively understand hazards without visual information is necessary. In this study, we focused on tactile sensation. The movement of surrounding objects was transmitted to the driver through a steering wheel using vibrotactile apparent motion. Firstly, we confirmed the highly intelligible characteristics of front-to-back, right-to-left, and back-to-front movements while holding a steering wheel. The direction of movement was transmitted using highly intelligible characteristics, and a positive effect was confirmed.

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To estimate the on-road emissions of Light-duty vehicles, Real Driving Emission (RDE) testing method is adopted. Engine operated duration of HEV and PHEV is shorter than that of conventional engine vehicles. At RDE test, we use the Portable Measurement Emissions System (PEMS). Conventional PEMS is continuously sampling emission during the engine-stop. Therefore, it is difficult to measure the correct emissions of HEV and PHEV. In this study, to estimate more correct RDE data, we validated another approach, which operate PEMS by intermittent sampling. As the result, there is a possibility that we obtain the correct RDE data of HEV and PHEV by using this approach.

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The real driving emission test will be implemented from October 2022 in Japan. For the efficient vehicle development, a test method for reproducing real driving conditions in the test conducted by using a chassis dynamometer is in demand. To replicate the wind speed and wind direction encountered during real driving in the chassis dynamometer test, we investigated a method of replacing the effect of wind condition with road gradients. The exhaust gas and fuel consumption of the vehicle in the chassis dynamometer test was found to be almost equivalent to that during real driving conditions when the vehicle speed, road gradient, ambient environment (temperature, humidity, solar radiation, and wind condition), and usage of air conditioner during real driving were replicated in the chassis dynamometer test.

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In this study an effect of the hole in the car body structure on the strength and the countermeasures by adding a flange to the hole edge were experimentally examined. The corner is not damaged by the hole, and the maximum load decreases even if a plane surface equivalent to Karman's effective width is left. It was demonstrated that the decrease in maximum load can be suppressed by setting a short flange on the hole edge. In addition, we examined the clarification of the flange shape that achieves both formability and performance using FEM analysis, and confirmed that even a flange with a formable shape has a strength recovery of 100％.

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Method for measuring a lateral displacement to a guide wire buried beneath the road surface in the field with the electro-magnetic guidance is proposed. Electro-magnetic guidance has been used for automated guidance of golf carts for several decades and proven its reliability. Currently, some of low-speed automated vehicles on public road use the same method for reliable operation. If a lateral displacement of a vehicle to the guide wire is easily measured, various type of vehicles can realize reliable automated driving on the road with electro-magnetic guidance. This paper proposes an electric module and algorithm for the above purpose and reports results of experimental evaluation.

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LiDAR plays an important role as external sensor for automated driving system. However, low-resolution 3D-LiDAR is insufficient that the point cloud data become sparse at long-range. This problem makes it difficult to obtain accurate information about the target object. To solve this problem, we propose an interpolation method, using sensor fusion with camera and LiDAR. And, RGB data from camera is used to search for corresponding point in adjacent frames. In addition, the searching range is determined by LiDAR’s depth data. We evaluated computing cost and shape reconstruction accuracy while applying our method into preceding vehicle. Furthermore, the point cloud data are carried out clustering and classification based on SVM.

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It is important to acquire the states of a car not only on test environments but also on real roads to realize a carbonneutral society. However, it is labor- and cost- inefficient due to the need of many in-car sensors. To alleviate this issue, this research acquires driving resistance coefficients by not directly measuring them but by predicting them using a neural network. In addition, we implement the proposed neural network model on an FPGA to enable its execution within the spare power of a car.

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This paper describes a visual object recognition method applicable for smart devices to identify crosswalks and pedestrian signals. The device, which is incorporated into a grip of handheld equipment, is capable to support users which have difficulty to recognize crosswalks. In this paper, a novel object detection methodology is proposed, which is a combination of CNN and computational visualization technology. By using the proposed object detection methodology, a smart assistant system for crossing roads is developed. The developed method exhibited highly accuracy recognition of the target objects.

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In this study, a nonlinear discrete model for rebreathing HCCI engines was developed, and engine control was performed based on the model. The constructed controller controlled the indicated mean effective pressure and maximum pressure rise rate by the fuel injection quantity and intake valve timing. Using both a LPV model and the nonlinear model in the controller made it possible to reduce the computational load and improve the transient performance.

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The suppression of knocking is one of the important issues for improving the efficiency of internal combustion engines. It is known from previous studies that NOx in recirculated exhaust gas contributes to the autoignition timing, and the effect on the autoignition timing varies depending on the amount of NOx and the atmospheric conditions. However, the detailed mechanism is still unclear. In this study, research on the elementary reaction of NOx based on reaction kinetics and a discussion of the effect of NOx addition using a modified reaction mechanism are reported.

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In order to make clear the oil consumption mechanism of automobile engines, theoretical calculation formulae have been proposed for the oil and gas flow behind the ring, drain holes and gaps of an oil control ring (OCR). Using the formulae, the oil flow through OCR into the piston 3rd land is predicted. The prediction suggests the amount of oil accumulated beneath the upper side rail highly affects the oil-up flow into 3rd land throughout the cycle.

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In recent years, the importance of torsional vibration reduction technology has been increased because reducing the number of cylinders of an engine leads to increasing the torque fluctuation from the engine and deterioration of the NV performance, and active research and development is under way. Among them, we have developed a variable dynamic damper (VDD) whose stiffness is continuously variable so that the resonance point follows the rotation speed. Transient dynamo tests assuming an actual vehicle were conducted and its performance was clarified. Furthermore, a theoretical analysis model was constructed and compared with the experimental results to clarify its validity.

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Recently, compactness of an e-Axle has been attracting attention. High speed rotation motor and its control are essential to realize the compact e-Axle. In this study, we proposed a new concept of synchronous 3 pulse control for high speed rotation e-Axle, and verified its effectiveness under maximum rotational speed 22,000 min-1 by using an actual motor. we will report the overview thorough the development process.

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The vehicle models are indispensable for the development of the steering systems, but there is a problem that the full vehicle models are complicated and there are many parameters to identify in order to incorporate them into the development process for the suppliers. Therefore, we developed a bicycle model-based vehicle model, in which the system requirement specifications for steering performance can be examined, using system identification based on actual vehicle measurements and confirmed its effectiveness.

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Analysis model of stator which can consider the influence of varnish is developed to reduce circular 0th vibration of stator. The rigidity of varnish is modeled as anisotropy of coil and the varnish impregnation ratio is modeled as connection area between coil and stator core. As a result, the difference in vibration level due to the change in varnish impregnation ratio can be predicted with an error of 0.2dB. It is revealed that the varnish impregnation ratio 40% to 60% is the best condition to reduce circular 0th vibration of stator.

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Operational Transfer Path Analysis (OTPA) is applied to a noise source contribution analysis for high thermal efficiency diesel engines. However, vibrations are transferred in an engine body by structure-borne, reference signals for OTPA are desired to contain assumed noise source components mainly. This paper describes some innovations which are tried to extract the desired components from the reference signals. In addition, this paper shows a mechanical noise prediction technique which combined OTPA and an empirical formula based on a vertical force of inertia and validation results by an engine test with reciprocating mass variations.

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The interaction between a Society of Automobile Engineers Level-3 automated vehicle and a driver is an important issue in automobile automation. We conducted a driving simulator experiment to investigate driver intervention during the system's emergency manoeuvre (EM) when encountering an imminent collision risk during automated driving. As a result of suspending EM due to driver intervention, collision risk decreased when no vehicles were adjacent. In contrast, collision risk increased when adjacent vehicles existed. Therefore, the results suggest that there are situations in which it is better to inhibit driver intervention during EM, such as when the driver steers toward an adjacent vehicle.

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Systematic 3-point bending crash tests were conducted with high strength steels using an M-shaped structure in order to influence the effect of material properties on crash performance. Materials with a wide range of tensile strengths from 590 MPa to 1800 MPa and various thickness from 1.2mm to 1.6mm are examined. The experimental results clarified the effects of sheet thickness, material strength on crash characteristics. Based on the experimental results, a simple method for estimation of bending crash performance using material strength and thickness as parameters was proposed in order to understand the relationship between the weight reduction effect and improvement of crashworthiness in automotive parts when using advanced high strength steels. Numerical simulation considering fracture behavior are carried out to estimate the crash performance and risk of fracture for the ultra-high strength steels. The results of the simulations shows good coloration with the experimental results.

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The sintering mechanism of Pd particles on the three way catalyst (TWC) was investigated by aberration-corrected environmental transmission electron microscopy (ETEM) which enabled us to measure under high temperature and simulated gas condition including H2, CO (as a reductant agent) and O2 (as an oxidant agent). In reducing condition over 900 degC, migration and aggregation of the Pd particles on Al2O3 were observed using ETEM. On the other hand, in oxidizing condition over 800 degC, we observed not only growing of the Pd particles but also becoming far smaller size particles and dispersion. In addition, it was found out that PdO existed in oxidizing condition. Hence we presumed that the growing of the Pd particles under oxidizing condition was due to re-aggregation of dispersed PdO nanoparticles. We studied the effect of the sintering of the Pd particles on a Pd-loaded support. The Pd particles on Matrix-B which suppressed oxidization of Pd kept smaller size than them on Matrix-A which advanced oxidized Pd.

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While MPC is a promising method of vehicle control, its performance is greatly affected by the accuracy of the prediction model. In addition, the prediction accuracy of existing vehicle models depends on the driving speed range. Therefore, this study proposes a new model and compares the control performance of MPC using candidate models on a simple path-tracking simulation over a wide driving speed range.

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In support of the CASE, PSIRT which becomes the basis of the security is indispensable. PSIRT is a team in charge of collecting security event then analyze whether the information has a potential to damage proprietary products. In the realization of PSIRT, the appropriate sorting and efficient processing of incident information will be a challenge. This study provides an intelligent technology using machine learning model to identify whether input information is automotive related by recognizing attack target of the contents. We evaluated this method by using collected vulnerability information and extracted the future work.

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For RTK positioning, integer ambiguity reliability judgment (Ratio-test) is often used. However, it is known that the ratio-test does not work effectively in multipath environments. In this paper, we propose an alternative method for determining the reliability of RTK positioning solutions that takes into account vehicle trajectories, with the aim of improving the usability of high-precision positioning in multipath environments.

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Traffic congestion near shopping centers or traffic accidents may be avoided by keeping away from specific lanes. Therefore, this study proposes a large-scale distributed data processing technique and a polygonal-shape based data search technique to detect traffic congestion at a higher accuracy than VICS. The implementation and experiments suggest establishment of a semi-real-time lane-by-lane traffic congestion detection method possibly be used for nationwide vehicle data.

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