We modeled the system as an equivalent three-inertia system and found out that the intercepts of the steering angle axis in the steering angle-torque characteristic diagram are caused by coulomb frictions and elastic deformations. Through a quasi-static analysis of the model, we formulated an assist control method and how to create a set of maps for the control method so that it compensates the effect of coulomb frictions and elastic deformations and realizes objective characteristics. We tested the proposed method by numerical simulation and an experimental bench.

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In the Three-year project, Next-Generation environmentally Friendly Vehicles Development and Commercialization Project, FTD (Fischer-Tropsch Diesel) truck optimized for 100% content FTD fuel was developed. Generally, FTD fuel has characteristics of zero sulfur, low poly-aromatic content and high cetane number. These characteristics results in lower soot and HC (hydro carbon) emission than a current diesel fuel. The engine modifications, such as lowering compression ratio and increasing EGR rate were implemented in order to take advantage of the characteristics of FTD fuel. The vehicles emission level is equivalent to the Japanese 2009 emission regulation.

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On-board measurement system with an exhaust gas analyzer were installed on test vehicles during road driving to analyze the correlation of the environmental factors such as the road slope and traffic flow and the appearance of NOx emission increase. On the basis of these data, we focused attention on the fuel cut control of the engine and following the various driving causing the NOx emission increase. These driving conditions were reproduced in the chassis dynamometer tests. And then we studied the evaluation method for the NOx emission increase during on-board driving by using the test method.

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Longitudinal and lateral forces acting on a traveling tire with slideslip angle due to the interaction with dry sand were measured under constant sinkage and slip ratio conditions by small size wheel test equipment. Based on the collected data, a tire model, which calculates longitudinal and lateral forces with sideslip angle, utilized for vehicle motion analysis on dry sand was approximately expressed as simple functions of sinkage and slip ratio. In order to verify the tire model, a numerical simulation and experiment of 4-wheel model vehicle driven with constant wheel velocities and fixed steering angles on flat sand were compared.

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The movement of average drivers' cars when passing through two non-signalized intersections without the right of way was measured. A laser distance meter and video cameras were used to follow their movements. Using time series data of car location, the speed profile of each car was drawn. The location and speed of the lowest speed and when each car passed through each intersection were analyzed. Then speed profiles between average and skilled drivers were compared to clarify the characteristics of the average driver's driving behavior while passing through an intersection. Finally, a typical dangerous driving behavior that causes an accident at an intersection was identified. The effect of the intersection environment on the typical dangerous driving behavior was also considered.

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This study examines a lane tracking control for motorcycles when running a curved path to develop a lane-keeping-assistance system. Two-degree-of-freedom controller which consists of feedforward and feedback controllers is designed for running a curved path. The feedforward control is based on a known curvature of a desired lane, and the feedback control is based on vehicle's state deviations from an equivalent point during a steady turning. This controller makes it possible to follow a desired lane in a curved section.

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It is known that in some conditions, shimmy phenomenon occurs on two-wheeled vehicles. However, detailed research with a full vehicle model has not been accomplished. In this paper, we first analyzed the experimental data and revealed that the increase of vehicle mass, front tire load ratio, the moment of inertia about the rear body yaw axis, and the decrease of the moment of inertia about the steering axis make a two-wheeled vehicle unstable. Then, a three-degree-of-freedom model with tire deformation was utilized to predict the shimmy. The results show the model can describe the observed shimmy phenomenon.

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Direct injected hydrogen internal engines have a high potential to achieve high specific power than port injected hydrogen engines. As this engine has sensitive characteristic of NOx emission to injection timing however, combination of variety of NOx reduction technology such as optimization of injection timing, EGR(Exhaust Gas Recirculation) and NSR(NOx Strage and Reduction) catalyst. This study describes the methodology how to build simulation model to satisfy NOx model is based on driving mode trace method that is required in the combination of NOx reduction technology mentioned above. As a result of the application of this model it has been found that a quarter of the NOx emission required by JE-05 driving mode will be obtained.

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Mode trace Simulation has been developed in a 1^st report. In this 2^nd Report, a verification of the simulation is assessed using experimental data from 6cyringers Hydrogen Engine. It was also predicted that high output power leveled to conventional diesel engine and NOx level of a quarter of the new-long-term regulation target by JE05 driving mode will be realized, by applying this model to the High pressure direct injection hydrogen engine potential with optimized injection timing, ignition timing, EGR and Rich Spike Management for NSR catalyst.

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The authors previously proposed a new stratified combustion concept in which the fuel injector is located in the center of the combustion chamber. Because this stratified combustion process forms a highly homogeneous mixture cloud, combustion is stable at the time of EGR. As a result, the process is characterized by an exceptionally low level of NOx formation. It is also characterized by the variation in the optimal piston cavity volume depending on the engine load and the large impact of the piston cavity volume on fuel economy. In the present study, a small concentric piston cavity was provided inside na extra large piston cavity for the purpose of expanding the operating load limits of stratified combustion. The effect of the inner cavity on the mixture formation process of stratified combustion and combustion characteristics was investigated along with examining the influence of the inner cavity geometry on engine performance.

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The effects of pressure on outwardly propagating laminar and turbulent flames were studied for iso-octane / air mixtures at the equivalence ratios from 0.8 to 1.4 and the initial pressures from 0.10 to 0.50MPa. Turbulence intensity was set to 0.80 and 1.59m/s. The Markstein number decreased for increasing pressures and for large equivalence ratios. The ratios of turbulent to unstretched laminar burning velocities at a constant Peclet number increased with increasing turbulence Karlovitz number and decreasing Markstein number at a constant pressure. However, the burning velocity ratios did not increase with increasing pressure although the Markstein number reduced with pressure.

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We have been working on a catalytic reaction dynamic simulation modeling as one of the most promising approaches to promote the effective development of the multi-functional catalyst in the next generation. Here we developed a one-dimensional micro-kinetic reaction model with detailed surface chemistry and with the mass transport inside the porous washcoat for a realistic automotive after-treatment catalytic system. This model can successfully predict the reaction dynamics of automotive catalysts in a wide range of real engine operating conditions. It implies that the effective catalyst designing can be realized in the near future by utilizing the present numerical simulation approach.

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This work is based on the standpoint that cycle-to-cycle combustion variations in spark-ignition engines under conditions of constant speed and load can result from the interplay of a chaotic dynamics of engine systems and a stochastic process. We propose a method to stabilize the chaotic behavior of the engine systems by adopting Pyragas' method for controlling chaos, and apply this method to an actual engine system in the idle state. The experimental results suggest that this method may stabilize the chaotic behavior to a periodic one.

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For the commercial production of gasoline HCCI engines, it is important that the effect of fuel characteristics on HCCI combustion and SI combustion. In this study, using the model fuels composed of paraffins, the effect of fuel characteristics on two Auto-Ignition phenomena, which are 1) HCCI combustion and 2) knocking in SI combustion, is analyzed with experimental and numerical approaches.

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Hydrogen Si-HCCI which is a new concept of HCCI combustion realized by applying spark ignition in hydrogen HCCI engine supported by DME supplement achieved controlling of onset of main heat release. As a result improvement in thermal efficiency was achieved by operating under so called the MBT conditions. In addition, the Si-HCCI enabled to reduce misfiring in high lambda conditions and mild and stable combustion in low DME mixing rate at low lambda condition. As a result large improvement in output power and expanding stable operating region were simultaneously achieved.

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In the premixed compression ignition combustion, high load region is limited by diesel knock, excess air ratio, maximum in-cylinder pressure and smoke emission. As a result of having examined it with variable effective compression ratio by using electro-hydraulic drive camless valve system and high pressure injection, premixed compression ignition combustion region was expanded to higher load side.

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The authors have applied flashing spray of a mixed fuel into premixed charge compression ignition to achieve low soot and NOx while keeping high thermal efficiency because it allows early fuel injection without suffering from wall-wetting of fuel or poor mixture preparation. In this case, however, the simultaneous ignition of homogeneous mixture causes combustion noise and knocking issue. To control the mixture heterogeneity and to suppress the rapid combustion, multiple fuel injections are employed in this paper. The combustion and emissions characteristics are evaluated for several combinations of secondary injection timings and quantity ratios of each injection event.

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The in-cylinder combustion process of a grou-hole nozzle was investigated by using a single-cylinder optical research engine. From the direct images of the flame, distribustions of the flame luminosity were analyzed. Two-color method was also employed to obtain flame temperature and KL factor. Effects of the group-hole nozzle on the combustion process were clarified by comparing with 6-hole nozzle and 12-hole Nozzle. In the case of the group-hole nozzle, the low soot formation during the combustion process and the low fuel consumption were achieved compared with the conventional 6-hole nozzle.

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To achieve the practical use of HCCI engine, it is important to keep robustness and high efficiency at high load. In this study, we construct and propose HCCI Combustion Control model using EGR control system. This system could change mixing ratio of three gases(stoichiometric pre-mixture, hot EGR gas and cold EGR gas) by using Throttle opening angle adjustment. Moreover, we make 2 different control methods(map control,feedback control) and evaluate them.

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The accumulation behaviors of impurities in hydrogen for fuel cell vehicles were investigated by using single cell test station equipped with a hydrogen circulation system. It was revealed that nitrogen and helium accumulate, but carbon monoxide, hydrogen sulfide and ammonia don't accumulate. Accumulation behaviors vary according to the different properties of impurities, such as adsorption property, reactivity, water-solubility and gas permeability. The accumulation behaviors of each impurity found in the present study will be reflected in the formulation of a hydrogen quality standard for fuel cell vehicles.

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In order to control the combustion in the direct-injection gas engine, characteristics of spark-ignition combustion of natural-gas jets injected into a constant-volume vessel were investigated under various conditions. Experiments for different injection pressures, ignition timings, and spark positions were made. Particularly, effects of the wake flow behind the cylinder body and the jet impingement on the wall for promoting ignitability and combustion were exhibited.

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Diesel-particulate trapping and oxidation in regeneration of a diesel particulate filter (DPF) made of SiC were investigated through visualization experiments using an All-In-Focus microscope and an infrared thermographic camera. In the trapping process, it was observed that PMs were trapped in the surface pores in the beginning of trapping. Then, a particulate cake was make on the wall surface. In the regeneration process, after the cake was removed by oxidation, the PMs trapped inside the pores reacted with oxygen.

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In this paper, sensitivity analysis was conducted by multi-dimensional CFD code coupled with complex chemistry analysis to investigate the dominant factor of diesel combustion. Heat release rate diagram was used for evaluating the effect of each parameter by comparing the shape of the diagram. The analysis revealed that the spatial density of oxygen is a very important determinant of the ignition timing in diesel combustion. Additionally, very simple equations were lead by the results of sensitivity analysis, and they could roughly predict heat release rate curve in extremely low CPU cost.

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In order to develop the performance of the LPG (Liquefied Petroleum Gas) engine, it is necessary to understand the flame propagation characteristics of C₃H₈, n-C₄H₁₀ and i-C₄H₁₀, which are the main components of LPG. In this study, the difference of the flame propagation characteristics between these hydrocarbons and regular gasoline was evaluated experimentally with the constant volume combustion chamber (CVCC). Furthermore, one-dimensional premixed laminar flame simulation was conducted to examine these combustion mechanisms. The result shows that C₃H₈ and n-C₄H₁₀, which are the normal paraffin in LPG, have the characteristics of higher laminar flame speed than gasoline and i-C₄H₁₀.

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Various fusion methods to estimate a vehicle trajectory using the Global Positioning System(GPS) and Inertial Measurement Unit(IMU) are proposed ordinary. We have started this study of the fusion algorithm for the vehicle trajectory measurment systems. At a midterm of this study, we developed the measurement systems to solve the cycle slip phenomenon and verified the vehicle precise trajectory for the short time. The applied positioning algorithm was Time Differential(ID) method. Finally, we have developed the real-time GPS-IMU fusion algorithm based on the discrete-time Kalman filter, which was described by a simplified linear state equation, through the higher performance of computer. In addition, real-time-fusion for GPS and IMU needs increased on the site. Our techniques showed good performances under various driving condition for hte findings of this development process.

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This paper deals with the influence of alcohol drinking to the driver vision. As the vision characteristics of drivers, the static vision, dynamic vision, ocular motor skill, visual acuity for depth, visual reaction time, peripheral vision, contrast sensitivity, and eye-hand coordination are examined for alcoholic driver. As the results, it is found that the visual feature of drivers are affected by the alcohol ingestion.

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The effects of Alpha-Pinene, which is a type of tree aroma, on decreasing the level of mental workload during car driving were investigated in a driving simulator with 13 participants. The positive effects on shortening reaction time to visual stimulus or keeping the appropriate time headway were shown, when the vaporized Alpha-Pinene was applied to the face of the driver with an optimized supplying sequence. The effectiveness in terms of preventive safety was also analyzed by comparison between the tree aroma and Forward Vehicle Collision Warming alarm. The supply of the tree aroma showed similar kinds of positive effects with the use of an alarm, such as keeping the appropriate time headway, when the driver's mental workload was increased after a continuous long drive.

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Tests conducted on actual roads in various driving situations of different degrees of difficulty revealed that the correct response rate of older drivers to an illuminated light in the peripheral visual field was lower than that of younger drivers. This indicated that the mental and physical workload of the older drivers was greater. To elucidate the reason for their poorer performance, driving situations of different degrees of difficulty were reproduced on a driving simulator and their reaction time and driving behavior were analyzed.

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Previous research has revealed that vestibulo-ocular reflex (VOR) is disturbed when the person is engaging in higher cognitive activities using either their auditory or fovea system. This present research extended it to the peripheral vision system. As expected, the participants showed the largest VOR disturbance while they were engaging in the 3-back task, the most mentally-demanding task in the 3 conditions. The results suggest that VOR disturbance has the potential to be a good measurement to detect conditions in which the driver is overloaded with too much mental workload and not capable of driving properly.

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The objective of the current study is to analyze the influence of changes of the physical motion on human body under low-level impact accelerations. Each subject sat on a seat mounted on the sled that glided forward on the rails and simulated actual car motion when the passenger applied the emergency avoidance maneuver. During the experiments, the physical motion, acceleration, and EMG(electromyography) signals were recorded. The posture control effect and the reflex time of each muscle differ from one region to the next. These results can contribute in clarifying the relationship between the physical motion and muscle forces with respect to the difference in activation level of muscles.

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A driving simulator capable of duplicating the critical sensations incurred during a spin, or when a driver is engaged in drift cornering, was constructed. Specifically, the simulator allows independent movement along three degrees of freedom and is capable of exhibiting extreme yaw and lateral acceleration behaviors. Utilizing this simulator, it is now understood that drivers responded chiefly to yawing and responded additionally to lateral acceleration by providing feedback to the motion, thus clarifying the characteristics of counter steering. It is understood by the eye-tracking behavior and perspiration levels that the yaw direction motion has a significantly greater impact on the driver than lateral acceleration.

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This paper evaluates a position of SOC (State of Charge) that indicates battery energy remaining along with a real world downhill drive to its simulation on an emission chassis dynamometer with a gradient road load. The real world data is measured by GPS (Global Positioning System) and fluctuates widely. A method of spline interpolation smoothes the data for a chassis simulation test. It was found that the SOC in the chassis simulation matches the SOC in a real world test. This chassis substitution method could be applied widely for simulation on a chassis dynamometer.

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In the small vehicle category, both ignitability and low cost are requirement. Currently the high ignitability spark plug does not meet the second requirement since they contain precious metals like Platinum and Iridium on their electrode. Considering these circumstances mentioned above, we have developed a superior wear restive material to achieve a fine-wired electrode design without the use of precious metals. Based on this development, we have introduced a new Super Ignition Spark Plug that achieves both high ignitability and low cost.

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Surface finish rolling experiments were carried out using rollers and spur gears of 1.5Cr-0.2Mo alloyed sintered steel having a density of 7.55g/cm³. A high precision CNC form rolling machine of 2 roller dies transverse type was employed. The rolling process was designed to get good surface layer densification and enough accuracy on the gear tooth profile. Single tooth bending fatigue test and rolling contact fatigue test were conducted. The experimental results show that the transverse form rolling for high density sintered steel material can be used to produce high precision sput gears with strength comparable to wrought steel gears.

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