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The non-physiological motions of human cervical vertebrae were analyzed in volunteer tests for rear-end impacts and were considered to be an important parameter for neck injuries. The objectives of this study are to improve the Marko de Jager neck model using volunteer test data and to analyze the influence of horizontal and vertical accelerations on cervical vertebral motion. In the beginning of this study, a neck model was positioned based on X-ray cineradiography of a volunteer. Motions of each vertebra were compared with those of volunteer test data for low speed rear-end impacts (4, 6, 8km/h). In these comparisons, the differences of vertebrae motions between the neck model and the volunteer tests were found. To improve the validity of the neck model, the connection properties and the bending properties of the upper and lower vertebrae of the model were modified to increase rigidity.

Acidified 2,4-dinitrophenylhydrazine (DNPH) solution, or DNPH-impregnated cartridges are commonly used for the collection of automotive exhaust carbonyl compounds. There are some DNPH-carbonyl compounds in not in use DNPH cartridges and DNPH solution. Furthermore, concentrations of automotive exhaust carbonyl compounds are decreasing according to improvement of the purification technology for automotive exhaust. Automotive exhaust carbonyl compounds become to be difficult to be analyzed with DNPH collection method, because of these two reasons. It is thought that reliable analysis of acrolein in automotive exhaust is very difficult because concentration of DNPH-acrolein in extracted solution is not stable. Furthermore, it is found out that DNPH-acrolein in DNPH-cartridge is disappeared for short time storage in this research.

For applying ISO 26262 to motorcycles, controllability classification (C class evaluation) by expert riders is considered an appropriate technique. Expert riders have evaluated commercial product development for years and can appropriately conduct vehicle tests while observing safety restrictions (such as avoiding the risk of falling). Moreover, expert riders can ride safely and can stably evaluate motorcycle performance even if the test conditions are close to the limits of vehicle performance. This study aims to construct a motorcycle C class evaluation method based on an expert rider’s subjective evaluation. On the premise that expert riders can rate the C class, we improved a test procedure that used a subjective evaluation sheet as the concrete C class evaluation method for an actual hazardous event.

In this study, a scheme for controlling the deceleration rate required to alleviate shockwave propagation in a vehicle platoon is proposed. Assuming a three-vehicle platoon, the deceleration rates of the 2nd and the 3rd vehicles were modeled so as to minimize the speed of the shockwave that propagates through the platoon. The effect of the decelerating two vehicles on a 4th following vehicle was also evaluated. Numerical analysis showed that an earlier and slightly more rapid deceleration rate significantly decreased the speed of the shockwave propagated by the first three vehicles. Furthermore, even though the shockwave was amplified through the 2nd to 4th vehicles, this negative effect could be eliminated by applying the same control strategy to the 3rd and 4th vehicles.

It was found that the finger blood pulse shows various fluctuations in different driving conditions. The nature of the finger blood pulse fluctuations was used for estimating a driver's internal state. Indexes suitable for expressing the fluctuations were moment and density; these indexes were calculated by using a return-map. However these results were measured by an off-line system and were calculated after the experiment. So, an on-line (real-time) system was needed in order to construct a driver's internal state monitoring system. As a first step, an online system for estimating the human internal state was developed. This system is available for estimating the human internal state every 30 seconds.

JAMA-JARI has developed a biofidelic flexible pedestrian leg-form impactor (Flex-PLI 2004) by making several modifications to the Flex-PLI 2003 to improve usability, durability and biofidelity. Biofidelity evaluation for the Flex-PLI 2004 was estimated at the component level (thigh, knee, and leg individually) as well as at the assembly level (thigh-knee-leg complex), using an objective impactor biofidelity evaluation system based on a method developed by Rhule et al. to eliminate any subjective prejudice in an impactor biofidelity evaluation. Applying the biofidelity evaluation system to the Flex-PLI 2004, the average impactor biofidelity rank (IBR) score became 1.22 at the component level and 1.26 at the assembly level. These IBR scores mean that the Flex-PLI 2004 has good biofidelity at the component level as well as at the assembly level.

A biofidelic flexible pedestrian leg-form impactor, called Flex-PLI, was developed by the Japan Automobile Manufactures Association, Inc. (JAMA) and the Japan Automobile Research Institute (JARI). Its latest version is called Flex-PLI 2003. The Flex-PLI 2003 responses have been validated at the component level (thigh, leg, and knee independently) but not at the assembly level (thigh-knee-leg complex). Furthermore, there was no FE Flex-PLI model. This research developed a FE Flex-PLI 2003R model (Flex-PLI 2003R means that the thigh and leg mass of Flex-PLI 2003 is adjusted to AM 50). The FE Flex-PLI 2003R model biofidelity has been evaluated at both the component level and the assembly level, where it demonstrated high biofidelity.

In this paper, an intersection collision warning system using DGPS (Differential Global Positioning System) will be proposed. The system is developed to prevent collisions of vehicles crossing at intersections, especially at well visibility intersections without traffic lights. Two GPS receivers are installed on two vehicles on the move towards the same intersection from different directions. The position and velocity information of the vehicles are measured by on-board GPS receivers, and then transmitted from one vehicle to another by inter-vehicle communication (IVC). Therefore, the relative position and direction of each vehicle and collision judgment coefficient (CJC) which is defined by using the relative position of vehicles are calculated. After taking the crossing position of directions and the variation of CJC into account, the position of the intersection and the possibility of collision can be predicted in advance. Warning will be given to drivers with a prearranged timing.

A numerical method specially designed to predict unsteady aerodynamics of road vehicle was developed based on unstructured Large-Eddy Simulation (LES) technique. The code was intensively optimized for the Earth Simulator in Japan to deal with the excessive computational resources required for LES, and could treat numerical meshes of up to around 120 million elements. Moving boundary methods such as the Arbitrary Lagrangian-Eulerian (ALE) or the sliding method were implemented to handle dynamic motion of a vehicle body during aerodynamic assessment. The method can also model a gusty crosswind condition. The method was applied to three cases in which unsteady aerodynamics are expected to be crucial.

In order to investigate the possibility of noise countermeasures taken on the road and in its surroundings an urban area exposed to high road traffic noise level was taken up as a model, and their effectiveness was estimated by a hybrid simulation method combining a scale model experiment technique and a computer simulation. The case studies of simulation were carried out in the case of improving the road structures, laying the noise barriers, constructing the noise-buffer buildings and so on. As a result, more than 20 dB (A) of road traffic noise reduction were obtained by a modification of the existing surface road to an elevated road.

Controllability (C) is the parameter that determines the Automotive Safety Integrity Level (ASIL) of each hazardous event based on an international standard of electrical and/or electronic systems within road vehicles (ISO 26262). C is classified qualitatively in ISO 26262. However, no specific method for classifying C is described. It is useful for C classification to define a specific classification based on objective data. This study assumed that C was classified using the percentage of drivers who could reduce Severity (S) in one or more classes compared with the S class in which the driver did not react to a hazardous event. An experiment simulated a situation with increased risk of collision with a leading vehicle due to insufficient brake force because of brake-assist failure when the experiment vehicle decelerated from 50 km/h on a straight road.

Controllability (C class) represents the level of the ability to avoid harm and is one of the parameters that determine the Automotive Safety Integrity Level in the ISO 26262 functional safety standard, which applies to the electrical and/or electronic systems. This study aimed to consider an appropriate C class evaluation technique for expert riders in applying ISO 26262 to motorcycles. This study attempted to show a C class evaluation method without deviation by the riders and presented examples of the evaluation of three hazardous events in actual vehicle tests. In addition, riders' comments regarding their understanding of the circumstances that resulted in the evaluation were collected, and the correspondence of these comments was examined. We selected “unintended acceleration” or “unintended deceleration” due to the malfunction of the electronic throttle control system as hazard examples and conducted tests to reproduce hazardous events.

Analysis of vehicle motion under conditions of lateral wind disturbance is important for evaluating handling properties and vehicle stability. In the analysis, identification of vehicle dynamics is often carried out, and data for the identification is usually measured by a test with a lateral wind generator. However, vehicle transient response in the test usually converges for a short duration because of the limitation of the wind width. If the identification carried out from this data by conventional methods such as FFT, fine frequency resolution is not gained. In this research, an identification method based on the autoregressive model (AR-method), which is robust for a phenomenon of short duration, has been applied to the analysis of vehicle dynamics under the conditions in order to solve the above issue.

Our study was conducted to demonstrate the primary factors involved in fires which result from an automobile's electrical wire harness system with fuses. In our experiments we used modeled automobile wire harnesses to study the processes of ignition and the resultant fires. Current was passed through blade type fuses to a portion of the harness and was intermittently short-circuited by a grounded metal plate. The nominal current ratings of the fuses we used were lower than or equal to 30 amperes [A], and the operating current was 30A at 12 Volts. Current flowed to the harness specimens through a DC power source. We found that electrical tracking with scintillation, caused by a weak electric flow through carbonized wire insulation, rarely generated flames in the wire harnesses without blowing the fuse. Ignition was never observed on the insulation near the areas shorted by the arc and/or overloaded currents going to the wire elements.

Crosscheck tests of fast electrical mobility spectrometers, Differential Mobility Spectroscopy (DMS) and Engine Exhaust Particle Sizer(EEPS), were conducted to evaluate the accuracy of fine particle measurement. Two kinds of particles were used as test particles for the crosscheck test of instruments: particles emitted from diesel vehicles and diluted in a full dilution tunnel, and particles generated by CAST. In the steady state tests, it was confirmed that the average concentration of each instrument was within the range of ±2σ from the average concentration of all the same type of instruments. In the transient tests, it is verified that the instruments have almost equal sensitivity. For application of the fast electrical mobility spectrometers to evaluation of particle number and size distributions, it is essential to develop a calibration method using reference particle counters and sizers (CPC, SMPS, etc.) and maintenance methods appropriate for each model.

To meet the strict emission regulations for diesel engines, an advanced processing device such as a Urea-SCR (selective catalytic reduction) system is used to reduce NOx emissions. The Real Driving Emissions (RDE) test, which is implemented in the European Union, will expand the range of conditions under which the engine has to operate [1], which will lead to the construction of a Urea-SCR system capable of reducing NOx emissions at lower and higher temperature conditions, and at higher space velocity conditions than existing systems. Simulations are useful in improving the performance of the urea-SCR system. However, it is necessary to construct a reliable NOx reduction model to use for system design, which covers the expanded engine operation conditions. In the urea-SCR system, the mechanism of ammonia (NH3) formation from injected aqueous urea solution is not clear. Thus, it is important to clarify this mechanism to improve the NOx reduction model.

One of the world's largest unsteady turbulence simulations of flow around a formula car was conducted using Large Eddy Simulation (LES) on the Earth Simulator in Japan. The main objective of our study is to investigate the validity of LES for the assessment of vehicle aerodynamics, as an alternative to a conventional wind tunnel measurement or the Reynolds Averaged Navier-Stokes (RANS) simulation. The aerodynamic forces estimated by LES show good agreement with the wind tunnel data (within several percent!) and various unsteady flow features around the car is visualized, which clearly indicate the effectiveness of large-scale LES in the very near future for the computation of flow around vehicles with complex configurations.

ISO 26262 (Road vehicles - Functional safety), a functional safety standard for motor vehicles, was published in November 2011. In this standard, hazardous events associated with each item constituting a safety-related system are assessed according to three criteria, namely, Severity, Exposure, and Controllability, thereby determining ASILs (Automotive Safety Integrity Levels) representing safety levels for motor vehicles. Although motorcycles are not included in the scope of application of the current edition of ISO 26262, it is expected that motorcycles will be included in the next revision. However, it is not appropriate to directly apply ASILs to motorcycles. In the first place, the situation of usage in practice presumably differs between motorcycles and motor vehicles. Accordingly, in this research, we attempted to newly define Motorcycle Safety Integrity Levels (MSILs).

This study addresses the virtual optimization of the technical specifications for a recently developed Advanced Pedestrian Legform Impactor (aPLI). The aPLI incorporates a number of enhancements for improved lower limb injury predictability with respect to its predecessor, the FlexPLI. It also incorporates an attached Simplified Upper Body Part (SUBP) that enables the impactor’s applicability to evaluate pedestrian’s lower limb injury risk also with high-bumper cars. The response surface methodology was applied to optimize both the aPLI’s lower limb and SUBP specifications, while imposing a total mass upper limit of 25 kg that complies with international standards for maximum weight lifting allowed for a single operator in the laboratory setting. All parameters were virtually optimized considering variable interaction, which proved critical to avoid misleading specifications.

In the urea SCR system, urea solution is injected by injector installed in the front stage of the SCR catalyst, and NOx can be purified on the SCR catalyst by using NH3 generated by the chemical reaction of urea. NH3 is produced by thermolysis of urea and hydrolysis of isocyanic acid after evaporation of water in the urea solution. But, biuret and cyanuric acid which may cause deposit are sometimes generated by the chemical reactions without generating NH3. Spray behavior and chemical reaction of urea solution injected into the tail-pipe are complicated. The purpose of this study is to reveal the spray behavior and NH3 generation process in the tail-pipe, and to construct the model capable of predicting those accurately. In this report, the impingement spray behavior is clarified by scattered light method in high temperature flow field. Liquid film adhering to the wall and deposit generated after evaporation of water from the liquid film are photographed by the digital camera.