A flexible ring-based model is simple, comprehensive, and accurate, and has been most frequently adopted in tire models with a low degree-of-freedom. Despite the importance of parameter identification techniques, the literature pertaining to the discussion of these techniques is insufficient. This paper presents a novel parameter identification method based on a three-dimensional flexible ring-based model for the tires of a passenger car using experimental modal analysis. This method is able to identify modal parameters by using experimental modal analysis and by using the model to calculate the model parameters for comparison with the modal parameters. The experimental modal analysis entailed the use of a method based on an iterative simultaneous equation and confirmed that it was possible to estimate the modal parameters with high accuracy. The recalculated results using the model parameters showed good correlation with the experimental results.

View full abstract

The introduction of highly automated vehicles will influence occupant seating behavior and seat design, including broader adoption of reclined seating postures. The goal of this study was to perform a preliminary assessment of the usability of two occupant FE models (NHTSA THOR FE, and GHBMC Simplified Occupant) to examine restraint interactions, occupant kinematics, and occupant protection challenges for reclined occupants in frontal collisions. During frontal crash simulations, the GHBMC simplified model tended to exhibit a greater propensity for submarining and greater forward flexion of the lumbar spine compared to the THOR model. These findings will help define needs for occupant protection research for reclined occupants in automated vehicles.

View full abstract

The oxidation degradation characteristics of four types of bioethanol fuel and one type of biodiesel fuel were investigated. It was found that rape methyl ester (RME) was the fuel that was most susceptive to oxidative degradation, whereas bioethanol fuels were resistant. Oxidative degradation of the fuels promoted the formation of fatty acids in the water phase. Once all formic and acetic acid contained in the oxidized RME was distributed in 0.1 vol% of the water phase, its pH was estimated to be ~1.6. Of the different stainless steel variants in the corrosion tests, which simulated the most severe conditions, SUS436L and SUS444 exhibited excellent corrosion resistance

View full abstract

The high fatality rate of the elderly in traffic accidents is one of the important issues in traffic safety. It is necessary to consider the influence of age and gender to reduce traffic fatalities of elderly occupants according to previous studies. The objective was to identify representative accident scenarios for elderly female occupants in side impacts. The Delta-V, PDOF and the most common seat track were identified using accident statistics. In addition, The influence of the seat track on thoracic injuries was investigated against the standard side impact protocol using a simulation model.

View full abstract

In order to reduce drag losses and a clutch actuator load, the new dog clutch system for stepped automatic transmission is developed. Transmitting torque is converted to the engaging force because rotating shaft and dog clutch are connected with the helix spline. The drag losses of this clutch are reduced by 50 to 60%, and the clutch actuator load is reduced by 50% compared to conventional multi-plate wet-type clutch.

View full abstract

Previous research shows that the power density of polymer electrolyte fuel cell can be increased by applying porous metal as a flow fields, supplying reactants evenly to the whole electrode areas as compared to the operation with conventional groove type flow fields. This paper investigates the effect of introducing none-woven metal fabric as flow fields. The investigations here revealed that the metal fabric shows higher maximum power output than groove due to a reaction resistance reduction. The effects above was observed in various flow feeds. The reduction of the resistance was significant in cathode, due to better water transport.

View full abstract

The technical progess in the areas of driver assistance and active safety leads to valuable information to be used prior to, during and even after a crash event. Car makers and suppliers can make use of this situation and currently develop Advanced Emergency Braking (AEB) Systems for Vulnerable Road Users (VRUs) such as cyclists to either avoid a collision or in a crash event to reduce injury risks of the participants. Within Europe test scenarios were already defined aiming to cover the most common crash scenarios. Considering the advances of such AEB systems their impact towards Japan accident situation is of highly interest. This paper describes the impact to a possible test setup derived out from analysis of Event Driver Recorder data from Japan. Finally a comparison against Euro NCAP test protocol for car AEB-Cyclist is done.

View full abstract

In this paper, we present our recently introduced “assistance on demand (AOD)” concept, which allows the driver to request assistance via speech whenever he or she deems it appropriate. The target scenario we currently investigate is turning left from a subordinate road in dense urban traffic. We first compare our system in a driving simulator study to driving without assistance or with visual assistance. The results show that drivers clearly prefer our speech-based AOD approach. Next, we investigate the differences between drivers’ left-turn behaviour in a driving simulator. The results of this investigation show that there are large inter-individual differences. Based on these results, we present another driving simulator study, where participants can compare manual driving to driving with a default and a personalized AOD system. The results of this second study show that the personalization very notably improves the acceptance of the system. Given the choice between driving with any of the AOD variants and manual driving, 87.5% of the participants preferred driving with the AOD. Finally, we present an evaluation of the AOD system in a prototype vehicle in real urban traffic.

View full abstract

Cellular V2X, initially defined under 3GPP Rel 14, establishes a baseline of direct device to device connectivity over cellular networks. Whereas traditional use cases may be enhanced with extended warning times, in fact a hybrid long range and short range approach requires further management of message timing and position tracking, combining differing latencies and multiple sensors into a seamless environmental view. Furthermore, the distances feasible in the presence of cellular infrastructure change the use cases, allowing for new far to near transitional cases, and providing impetus for a more integrated HMI combining information, warning, and safety messages.

View full abstract

Traumatic brain injury (TBI) is the leading cause of death and permanent impairment over the last decades. In both the severe and mild TBI, diffuse axonal injury (DAI) is the most common pathology. Computation of axon elongation by using finite element (FE) head model in numerical simulation can enlighten the DAI mechanism and help to establish advanced head injury criteria. The main objective of this study is to propose a brain injury criterion per age-class based on multiscale computation of axonal elongation of real world head trauma. The implementation of advanced skull mechanical properties and new medical imaging data such as fractional anisotropy and axonal fiber orientation from Diffuse Tensor Imaging (DTI) into the FE brain model was performed to improve the brain constitutive material law with more efficient heterogeneous anisotropic visco-hyper-elastic material law and enables it to compute axon elongation at the time of impact .Further, well-documented head trauma cases were simulated by using this finite element head model in order to derive head injury criteria for different injury mechanisms. Coming to brain injury, the head trauma database was divided into three different groups depending on victims’ age: under 30 years old, between 30 to 50 years old and over 50 years old. An extensive real-world head trauma simulation exercise including age-class analysis was performed on an advanced head FE model including the computation of axonal elongation. Based on the statistical analysis, axonal strain was the most relevant candidate parameter to predict moderate DAI. It was showed that the threshold value in terms of axonal strain for a 50% risk of moderate DAI decrease with the increase of victim’s age. Senior people seem to be more sensitive to moderate DAI than the other age-classes.

View full abstract

Automotive Original Equipment Manufacturers (OEMs) are taking more control of Electronic Control Unit (ECU) hardware/software architecture definition and exploration mainly due to the rise of new technologies in ADAS and autonomous vehicles. The increasing number of cars with ECUs containing tens of processors, and the need to accelerate the simulation of thousands of driving scenarios and design parameters to ensure safety and reliability in autonomous driving has expanded the use of Hardware Emulation-In-The-Loop based on its capacity and functional verification merits. In this paper, an integrated heterogeneous system of systems framework to simulate and verify multiple ECUs is presented. The framework allows co-development of the automotive system application software, operating system and controller hardware together with the mechanical system actuators, sensors, and the physical world environment/traffic scenarios all in one. A comprehensive manual/automatic braking system use case consisting of four ECUs at different levels of abstraction is used to demonstrate the tools and interface technologies developed in-house and integrated with third-party tools.

View full abstract

Particle number exhaust emissions from diesel – and recently – from gasoline direct injection engines have already been regulated for particle sizes larger than 23 nm. However, interests have been extended to different applications and also to particles smaller than 23 nm. The UNECE Particle Measurement Programme (PMP) group is currently evaluating the feasibility to measure the sub-23 nm particle emissions by modifying the existing methodology. This paper focuses on the associated challenges of particle number measurement instruments in terms of sampling and diluting the emissions as well as of counting the sub-23 nm particles.

View full abstract

The ash deposition process on the wall surface of a diesel particulate filter was investigated through time-lapse visualization utilizing a field-emission scanning electron microscope. The components of zinc and phosphorus included in the primary particles of particulate matter (PM), as well as other large ash particles consisting of calcium, zinc, sulfur, and phosphorus in a PM cake layer, were sintered as an ash layer. These ash components were deposited locally around the perimeters of surface pores during a regeneration process. The pressure drop in the filter was reduced by the growth of the ash layer.

View full abstract

In previous report, the fatal accidents in hilly and mountainous area are paid attention to Nagano prefecture using statistical accident data analysis. Also, it was found that Wakayama and Yamanashi prefectures etc. belong to same cluster. This paper analyzed the comparison among these prefectures to clarify Nagano's and each cluster’s characteristics of accidents in detail. Principal component analysis was performed to clarify the characteristics of each cluster and remarkable accidents. Furthermore, the feature was verified by classifying and investigating fatal accidents in Nagano occurred in 2016. As a result, remarkable accidents of Nagano were vehicle to vehicle and vehicle alone accidents on the road with up-down slope and curve in hilly and mountainous areas. It was found that approximately 19% of fatal accidents in Nagano were these types of accidents. In addition, the principal component analysis indicates Wakayama and Yamanashi have the same characteristics of accidents as Nagano. This method for accident analysis is valuable to find out characteristics and their true causes toward zero accidents in local areas.

View full abstract

A new equation, which was dependent on physical principles, was developed for the study of heat transfer in CI engines which needs turbulence of gas flows to calculate heat flux. Proposed approach was implemented into a 1-D engine simulation, which was used to determine heat flux between in-cylinder gas and wall. Results from the suggested equation were compared to the previous conventional equations; Morel and Hohenberg, and to the engine experiments. The proposed equation showed better accuracy when compared with the conventional equations due to detailed representation of in-cylinder gas flow by dividing the combustion chamber into 6 different regions.

View full abstract

Due to the excellent heat transfer characteristics, the spiral coil sub-cooled condenser(SCSCC) has a bright application for the prospective automotive air-conditioning system. The engine load and emissions can be diminished by increasing the coefficient of performance of the vehicular A/C unit because this load is the second power consumption unit after the engine. Experimentally, two different cross-sectional channel of SCSCC has been analyzed and then compared with CFD investigation. The CFD results revealed the generation of Dean vortices inside the refrigerant and illustrate the co-relationship among heat transfer rate and pressure loss inside SCSCC

View full abstract

The electrodes and especially the separator of a lithium-ion-cell are exposed to mechanical stress due to expansion of electrode materials during operation if the electrodes are integrated in a stiff cell casing e.g. in a 18650 cell. As a result, the porosity and therefore the lithium-diffusion characteristics are altered. In this paper a simulative study of spatially resolved effects from inhomogeneous separator porosity reduction induced by mechanical strain is presented. The findings show significantly changed spatial current densities and local anode voltage potentials that match findings of post-mortem investigations.

View full abstract