Defining a “user driver″ is one of the important activities for designing driver support systems and its interface. To make a user profile efficiently and appropriately, the questionnaires that characterize drivers by their attitude and workload consciousness were translated into the local language and were evaluated primarily. Next, field study that has three stratified investigation, such as questionnaire, interview and observation was conducted. In the fieldwork, a distinctive driving posture was observed. And then, three user profile examples characterized by sitting posture were shown. As a result, the validity and the effectiveness of study procedure are verified.

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Three-axis acceleration, yaw velocity and roll velocity can be measured using two electronic stability control (ESC) sensors, which are orientated at 90 degrees to each other. In this paper, a vehicle attitude observer using this arrangement is proposed. The proposed method compensates for the zero drift of in-vehicle sensors and accurately estimates the vehicle attitude

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This paper discusses the 2-out-of-3 hot standby electronic control unit (HECU), which has a characteristic of fault tolerance, from a viewpoint of functional safety. Firstly, the logic of malfunctioning-events caused by the HECU is modeled by use of state-transition diagrams. Next, malfunctioning-event rates are formulated based on the diagrams by taking independent-dangerous and common-caused-dangerous failures of HECU, as well as the demands on the HECU into account. Then, the relationship between the operational time, i.e., the duration in which the motor vehicle could be driven under the normal or degraded HECU, and the malfunctioning-event rate is analyzed. Thus, it is concluded that the approach presented by this paper is useful for the functional safety assessment of HECU.

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The key point of the research is to improve the eco-driving performance in a hybrid truck among various types of drivers. An investigation relationship between the driver control parameters, driving performance and fuel economy has shown a potential to improve fuel economy and reduce the dispersion of fuel economy among various types of drivers by improving the vehicle longitudinal dynamics. Then, a hybrid vehicle controller consisting of an automatic gear controller and a hybrid torque distribution controller with a driving torque feedback compensator is designed. The automatic transmission controller calculates the optimal transmission gear ratio and the desired torque considering fuel economy. The hybrid torque distribution controller with a driving torque feedback compensator considering the torque response of hybrid system is designed. Finally, the effectiveness of the system is verified by simulations. The result indicates that the driving performance and fuel economy of the HEV was improved by using proposed hybrid control system.

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We investigated optimal swivel control on curves of winding roads as a function of driver's age and gender. In a field experiment using a test vehicle at the test track of the Denso Abashiri Test Center in Hokkaido, 36 subjects were surveyed on their preference for the swivel control system under driving situation. In the experiment, we set five swivel control systems varied from no swiveling system to predicting swivel system. The subjects rounded the test truck under a swivel control system and assessed that system subjectively. We applied an ordered logit model for estimating effect of driver's attributes and visual functions on assessments of the five swivel control systems. It was found that the swivel system to illuminate at three seconds ahead of the current position is selected as the best preferred system.

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The aim of this paper is the understanding of knocking occurrence mechanism from the view of flame propagation behavior by using 3-D simulation with UCFM. The flame propagation behavior impacted by in-cylinder flow was analyzed by calculated results and experimental visualizations. The flows of tumble and swirl motion were given to in-cylinder by setting various baffle plates in the middle of intake port. The comparisons of the measured and calculated flame propagation behavior show good agreement for various conditions. The results indicate that in-cylinder flow varies flame propagation shape from initial combustion, and it has strongly influence on knocking occurrence.

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Exhaust Gas Recirculation (EGR) is one of the techniques for reducing NOx emissions. EGR gas consists mainly of N₂, H₂O and CO₂. Properties of flame diluted with EGR gas might be influenced by these components. The effects of dilution with N₂ on outwardly propagating laminar and turbulent flames were studied for stoichiometric iso-octane/air mixtures at the initial pressures from 0.10 to 0.50 MPa. The dilution rate, defined as the molar fraction of dilution gas in the air and dilution gas, was varied up to 0.10. The properties of diluted flames were discussed comparing N₂ and CO₂ dilution.

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Some authors had proposed an idea of HCCI timing control with CH₂O addition to an air/hydrocarbon fuel mixture. When reactions start with LTO (low-temperature oxidation or cool-flame reaction), the addition retards the ignition timing. When reactions start without LTO, the addition advances the timing. These opposed impacts on the ignition timing were explained by a kind of reaction path analysis, based on a universal rule of hydrocarbon fuel oxidation proposed by other authors. With LTO, the CH₂O retards LTO by scavenging OH, resulting in the negative impact. Without LTO, that is at high temperatures in the process, H₂O₂ generated from fuel and the CH₂O enhances the heat release rate of a loop of reactions, H₂O₂→2OH+M, CH₂O+OH→HCO+HO₂, HCO+O₂→HO₂+CO, 2HO₂→H₂O₂+O₂, leading to the positive impact. H₂O₂ addition to a mixture advances LTO by supplying initial OH, and also enhances the heat release rate of the loop. What is to be noted is that those impacts of CH₂O and H₂O₂ addition on reactions can be on an additivity rule.

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Methyl-butanoate is a surrogate for biodiesel fuels. This methyl-ester reaches ignition without remarkable low-temperature oxidation and shows longer ignition delays than n-heptane at low initial temperatures. However, it shows shorter ignition delays than n-heptane or iso-octane at high initial temperatures. The high ignitability of methyl-butanoate was analyzed by the contribution matrices of all elementary reactions to formation of all species and heat release. This fuel has an efficient CH₃O formation path via CH₃ and direct CH₃O formation paths, both characteristic of methyl-esters. The CH₃O concentration is extremely high in the ignition preparation period. The rich CH₃O decomposes into H and CH₂O. Then, H combines with O₂ into HO₂. This exothermic reaction is activated even immediately after the reaction start, resulting in the short ignition delay

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The optimization method of DI engine parameters (piston shape, injector, injection pattern, swirl ratio, and so on) by KIVA-3V was developed. This method uses RSM (Response Surface Model) and RSM is rebuilt after each calculation is finished, leading to reduce the total calculation time for finishing engine parameter optimization.

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The trapping and regeneration of particulate matter (PM) viewed on the surface of diesel particulate catalyst-membrane filters (DPMFs) were investigated in detail using an All-In-Focus optical microscope. To improve filtration efficiency, a SiC DPMF with K- and Na-zeolite catalyst membranes and a cordierite membrane diesel particulate filter (DPF) with a Pt on alumina ceria catalyst were developed and evaluated successfully. Visualization results showed that trapped particulates were distributed only along the morphology of the membrane′s top surface. In the regeneration process, trapped particulates shrank gradually with time. The particulate oxidation temperature for zeolite catalyst membranes was about 100 °C lower than that for a noncatalyst DPF. The activation energy of particulates on zeolite catalyst membranes was about 26 to 30 kJ/mole lower than that on a noncatalyst DPF. Thus, K- and Na-zeolite membranes have almost the same catalytic activity as a cordierite membrane with Pt on alumina ceria.

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The purpose of this study is to apply the internally geared hypocycloid mechanism to diesel engines for automobiles in place of a piston crank mechanism, and to produce the mechanism for the engine which realizes a low fuel cost, high efficiency and a clean exhaust gas. In this report, the opposed piston mechanism is designed for a horizontally opposed type 4-cylinder 4-stroke diesel engine and the possibility of the utility is examined in comparison with the corresponding practical engine. As a result, it is presented that the opposed piston mechanism is considered to be valid structurally for the above purpose.

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A palm-sized hydrogen sensor using ultrasonics for automotive application is demonstrated at temperatures from -10 to 50°C. The sound velocity of hydrogen is about four times larger than that of the air. Therefore, it is possible to measure hydrogen concentration in the open air by just measuring the sound velocity difference before and after the hydrogen leak. The measurement method is simple and similar to the measurement of a distance by ultrasonic which is well established. It is shown that the distance between ultrasonic probes can be as small as 20mm which can be as possible size for the detection head. Since the detector is measuring the sound flight time between two probes, the detectin time of this sensor can be less than 0.1msec; therefore, this method is practical for detecting the hydrogen leakage in order to immediately shut down the valves.

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Analysis of vehicle-pedestrian conflict data, which was collected by active safety driving recorder, have suggested that drivers' detection performance for pedestrian walking on crosswalk is critically affected by increment of safety confirmation requirements. In order to verify the negative influence, replication experiment was conducted in test road that simulated actual road configuration, and a mobile robot was used as a simulated pedestrian. Degraded pedestrian detection performance was successfully observed according to increment of drivers' scanning directed to locations other than a pedestrian approaching.

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In order to build a useful and comfortable in-car human machine interface systems,the information presentation method should be easy to understand (low mental workload). Moreover, the driver should be able to respond with ease to the presented information (low response workload).We are trying to establish an evaluation method of the mental workload independent to the response workload. Here, we present the results of our trial using brain waves measurements (Event Related Potentials). We focus on the relation between P3 latencies and drivers response workload compared to mental workload.

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We carried out transient analysis of stirred fluid flow with rotating gear using the particle method (MPS method). The particle method is widely used as an effective technique for free surface flow and also easy to treat the moving boundary. In this research, we focused on the fluid resistance of gear and verified the correspondence with the experiments with two types of gear and two types of rotational rate. As a result, we found that the simulation value of stirring torque was consistent with experimental value in case of low rotational rate.

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This paper discusses improvement of the method for detecting biomechanical distraction via analysis of static pressure distribution on the driving seat. The previous research showed that a detection method, which extracts the Higher-order Local Auto-Correlation (HLAC) feature from a single pressure distribution, was not high enough as a reliable method. Based on detailed review of the result, we propose combining sensors on the seat cushion and the backrest instead of using just the sensor on the seat cushion, and making the learning data set which has wide varieties for robust recognition. The result of an experiment shows that the mean recognition rate was approximately 85% suggesting the effectiveness of the detection method.

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Toyota has been evolving a hybrid system since introducing the first mass-production hybrid vehicle in 1997 in response to the increasing automotive-related issues of CO₂ emission, energy secirity, and urban air pollution. This paper describes a newly developed hybrid system design and its performance. This system was developed with the main purpose to improve fuel consumption, especially for better real world fuel consumption; and to enhance its compatibility with multiple vehicle adoption by downsizing and reducing the weight of its xomponents. At the same time, the hybrid system achieved improved power performance while satisfying stringent emission regulations in the world.

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The development of fuel cell hybrid vehicles (FCHV) started in 1990s and they are currently being improved to resolve the issues for commercialization. This research focused on one of the main issues of a fuel cell (FC), namely the water content of the electrolyte membrane, to develop an FC water content control system based on the measurement of AC impedance. Adopting this control system in an actual FCHV resolved the issue of reduced efficiency caused by the membrane drying up, and it became possible to start up the FCHV in temperatures of -30°C by performing the appropriate water content control for freezing environments.

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New 2.0 liter L4 DI diesel engine which achieves the best performance in its class with the new technologies like piezo-electric injector and meets Japanese new emission regulation(Post New Long Term) with Lean NOx Trap Catalyst (LNT) that is the first application for diesel in the world, is developed.
This paper introduces outline of the engine and the performances.

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Emission control systems with NOx trap catalyst have been developed for meeting the strict emission regulations. In this development, particularly, it is difficult to create the technologies for lambda control without affecting the drivability. In this study, the new lambda control system was developed, and applied the 2.0 liter diesel engine. In result,the new emission control system was achieved to meet the Japan 2009 emission regulation.

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To provide for diesel fuel diversification in the future, it is necessary to clarify the effects of each fuel specification on the combustion and emissions characteristics of a state-of-the-art engine. Fischer-Tropsch synthetic Diesel (FTD) fuels have characteristics of higher Cetane number and very low poly-aromatic hydrocarbon content. In this work, the effect of specific FTD fuel characteristics on diesel combustion and emissions were firstly compared with diesel fuel by means of a multi cylinder engine and a single cylinder transparent engine. From these findings, engine modifications for neat FTD fuel were then studied to improve both emissions and fuel consumption.

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By the results of computer simulation with orthogonal polynomial expansion of quality engineering performed on drivetrain bending vibration with propeller shaft, the followings have been clarified. Using an additivity of factorial effects of first-order coefficient of orthogonal polynomial expansion and selecting signal factors separated into the case of short length and long length of propeller shafts, we propose a conditional inequality of design parameters that meet the objective values. Then, we propose a sliding approach of control factors based on the conditional inequality, and a sliding approach of control factors based on S/N ratio and first-order coefficient, in order to obtain optimal solutions. By applying the aforementioned conditional inequality and the sliding approaches to drivetrain bending vibration of heavy duty truck, we could tune the vibration levels to objective values with the design parameters.

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Exhaust emissions behavior from a vehicle under road driving condition is affected by the driving force of a vehicle. It is impossible to measure the driving force by the existing torque meter under this road driving condition. This study reports the development and verification of the wheel torque meter which is possible to measure driving force under the on-road driving condition and have enough strength and accuracy. As a result of verification, the wheel torque meter developed in this study has high accuracy under both the chassis dynamometer test and the on-road driving condition.

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