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Vehicle’s Front End Profile Influence on Pedestrian Sensing System Using In-House Developed PDI-2 and Child FE Models

Nissan Motor Ltd.-Chinmoy Pal, Tomosaburo Okabe, Munenori Shinada, Kazuto Sato
RNTBCI-Kulothungan Vimalathithan, Jeyabharath Manoharan, Pratapnaidu Vallabhaneni
Published 2016-04-05 by SAE International in United States
Many active safety systems are being developed with the intent of protecting pedestrians namely; pedestrian airbags, active hood, active emergency braking (AEB), etc. Effectiveness of such protection system relies on the efficiency of the sensing systems. The pop-uphood system was developed to help reduce pedestrian head injuries. A pop-up system is expected to make full deployment of the hood before the pedestrian’s head could hit the hood. The system should have the capability to detect most road users ranging from a six year old (6YO) child to a large male. To test the sensing system, an impactor model (PDI-2) was developed. Sensor response varies for vehicles with different front end profile dimensions. To study numerically the sensor response characteristics with respect to different front end parameters, (a) PDI-2 FE model was developed and validated, (b) FE model of sensor was developed and validated, (c) Sensor FE model was incorporated in the vehicle and it was simulated against the PDI-2 FE. The results were validated with physical experiments, (d) Vehicles with different front end profile models…
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Effect of Vehicle's Front End Profile on Pedestrian's Lower Extremity Injury Pattern in Real World and Verification by Large Male FE Human Model

Nissan-Chinmoy Pal, Tomosaburo Okabe, Munenori Shinada
RNTBCI-Kulothungan Vimalathithan, Jeyabharath Manoharan
Published 2015-04-14 by SAE International in United States
Logistic regression analysis for accident cases of NASS-PCDS (National Automotive Sampling System-Pedestrian Crash Data Study) clearly shows that the extent and the degree of pedestrian's lower extremity injury depend on various factors such as the impact speed, the ratio of the pedestrian height to that of the bonnet leading edge (BLE) of the striking vehicle, bumper to knee ratio, bumper lead angle, age of the pedestrian, and posture of the pedestrian at the time of impact. The pedestrian population is divided in 3 groups, equivalent to small-shorter, medium-height and large-taller pedestrian with respect to the “pedestrian to BLE height-ratio” in order to quantify the degree of influence of lower leg injuries in each group. Large adult male finite element model (95th percentile male: 190 cm and 103 kg) was developed by morphing the Japan Automobile Manufacturers Association (JAMA) 50th percentile male. Lower extremity of developed large male was fine meshed to predict the fractures accurately. A car model was systematically morphed to create different designs having various front end profile dimensions. Large male model with…
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Estimation of Pelvis Injuries and Head Impact Time using Different Pedestrian Human FE Models

Nissan-Chinmoy Pal, Tomosaburo Okabe
RNTBCI-Kulothungan Vimalathithan, Jeyabharath Manoharan, Muthukumar Muthanandam, Satheesh Narayanan
Published 2014-04-01 by SAE International in United States
A logistic regression analysis of accident cases in the NASS-PCDS (National Automotive Sampling System-Pedestrian Crash Data Study) database clearly shows that pedestrian pelvis injuries tend to be complex and depend on various factors such as the impact speed, the ratio of the pedestrian height to that of the bonnet leading edge (BLE) of the striking vehicle, and the gender and age of the pedestrian. Adult female models (50th %ile female AF50: 161 cm and 61 kg; 5th %ile female AF05: 154 cm and 50 kg) were developed by morphing the JAMA 50th %ile male AM50 and substituting the pelvis of the GHBMC AM50 model. The fine-meshed pelvis model thus obtained is capable of predicting pelvis fractures. Simulations conducted with these models indicate that the characteristics of pelvis injury patterns in male and female pedestrians are influenced by the hip/BLE height ratio and to some extent by the pelvis bone shape. A previously developed six-year-old (6YO) child pedestrian model and the newly developed models were used to estimate the head impact time (HIT) for a typical…
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Estimation of Body Mass Index Effect on Lower Extremity Injuries for Lateral Collision With-out Airbag

Nissan-Chinmoy Pal, Tomosaburo Okabe
RNTBCI-Kulothungan Vimalathithan, Muthukumar Muthanandam, Jeyabharath Manoharan, Satheesh Narayanan
Published 2014-04-01 by SAE International in United States
A comprehensive analysis was performed to evaluate the effect of BMI on different body region injuries for side impact. The accident data for this study was taken from the National Automotive Sampling System-Crashworthiness Data System (NASS-CDS). It was found that the mean BMI values for driver and front passengers increases over the years in the US. To study the effect of BMI, the range was divided into three groups: Thin (BMI<21), Normal (BMI 24-27) and Obese (BMI>30). Other important variables considered for this study were model year (MY1995-99 for old vehicles & MY2000-08 for newer vehicles), impact location (side-front F, side-center P & side-distributed Y) and direction of force (8-10 o'clock for nearside & 2-4 o'clock for far-side). Accident cases involving older occupants above 60 years was omitted in order to minimize the bone strength depreciation effect. Results of the present study indicated that the Model Year has influence on lower extremity injuries. Occurrence of pelvis injury was found to be influenced by BMI and was validated with logistic regression analysis. Apart from BMI, gender…
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Flex-PLI Application to High-Bumper Vehicles - Optimization of Supplemental Weight

SAE International Journal of Transportation Safety

Nissan Motor Company, Ltd.-Yoshiko Kawabe, Chinmoy Pal, Hiroyuki Okuyama, Tomosaburo Okabe
  • Journal Article
  • 2013-01-0215
Published 2013-04-08 by SAE International in United States
The Flexible Pedestrian Legform Impactor (Flex-PLI) was developed to evaluate the risk of pedestrian lower extremity injuries. However, it has been pointed out that the post-crash kinematics of the Flex-PLI differs from those of a human body when it is hit by high-bumper vehicles. This paper describes the feasibility of applying the Flex-PLI to a wide range of vehicle types by adding a supplemental weight. The following aspects are discussed in this regard: A human body finite element (FE) model analysis shows that the upper body of the Flex-PLI is not involved in tibia and knee ligament injury indexes in the first contact with a high-bumper vehicle.A rigid bar model is introduced and its rotational energy ratio is formulated. The rotational energy ratio is employed to evaluate the post-crash kinematics of the Flex-PLI and a human leg model.The feasibility of adding a supplemental weight to the Flex-PLI with regard to the bumper height is discussed.
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Comparison of Dummy Kinematics and Injury Response between WorldSID and ES-2 in Side Impact

SAE International Journal of Transportation Safety

Nissan-Kazuya Iwata, Kaoru Tatsu, Hidetsugu Saeki, Tomosaburo Okabe
  • Journal Article
  • 2013-01-0599
Published 2013-04-08 by SAE International in United States
A new highly biofidelic side impact dummy, the WorldSID 50th percentile male, has been developed under the supervision of the International Organization for Standardization in order to harmonize a number of existing side impact dummies in one single dummy. Momentum is growing for using the WorldSID in safety tests in the EU and the US. In the present study, two Euro-NCAP pole side impact tests were conducted to compare ES-2 and WorldSID responses in a mid-size SUV with respective seating positions as stipulated in the Euro-NCAP test conditions and fitted with the same side airbag. It was found that, compared with ES-2, the chest, abdomen and pelvis accelerations of WorldSID are more sensitive to variation in the applied external load transmitted by the deployed side airbag and door intrusion.
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Method Development of Multi-Dimensional Accident Analysis Using Self Organizing Map

SAE International Journal of Transportation Safety

Nissan-Hitoshi Uno, Yusuke Kageyama, Akira Yamaguchi, Tomosaburo Okabe
  • Journal Article
  • 2013-01-0758
Published 2013-04-08 by SAE International in United States
Implementation of appropriate safety measures, either from the viewpoint of a vehicle or the society or the infra-structure, it is an important issue to clearly understand the multi-dimension complicated real world accident scenarios. This study proposes a new method to easily capture and to extract the essence of such complicated multi-dimension mutual relationship by visualizing the results of SOM (Self Organizing Map).The FARS data from 2010 is used to generate a dataset comprised of 16,180 fatal passenger car drivers and 48 variables. The 16,180 fatal drivers were clustered using hierarchy cluster analysis method and mapped into a two-dimensional square with one dot representing one fatal driver using SOM.From the SOM assessment of the 16,180 fatal drivers, five clusters were created, and they are characterized as follows: Cluster 1 (Interstate highway accidents), Cluster 2 (Drunk speeding), Cluster 3 (Non speeding lane departure), Cluster 4 (Vehicle to vehicle) and Cluster 5 (Intersection).The number of fatalities in Clusters 1 and 2 could be possibly reduced by application of CA (Crash Avoidance) technologies and stricter enforcement of traffic laws.…
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A Study of Rear Seat 6YO Dummy Kinetics in Frontal Crashes~Part II

Nissan Motor-Takashi Deguchi, Kaoru Tatsu, Akira Yamaguchi, Tomosaburo Okabe
  • Technical Paper
  • 2012-08-0302
Published 2012-05-23 by Society of Automotive Engineers of Japan in Japan
Better protection of children-females and older people-who often sit in the rear seat, is very important to achieve the further improvement for rear seat occupant safety. Offset frontal crash tests were conducted using two types of test dummies, a Hybrid III 6YO and a Q6 dummy, and two different dummy positions in the rear seat, impacted side and non-impacted side. The comparison of dummy kinetics in the full vehicle crash tests showed that the chest deflection tended to be larger in the dummy positioned in the non-impacted side than in the impacted side.
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Influence of Structural Difference of WorldSID and ES-2 in Side Impact

Nissan Motor-Ryuuji Ootani, Kimio Hikasa, Kaoru Tatsu, Akira Yamaguchi, Tomosaburo Okabe
  • Technical Paper
  • 2012-08-0301
Published 2012-05-23 by Society of Automotive Engineers of Japan in Japan
At present, under the supervision of ISO (International Organization for Standardization) a highly biofidelic new side impact dummy "WorldSID 50th Percentile Male" has been developed in order to harmonize a number of existing side impact dummies in one single dummy. The WorldSID is gaining momentum to be implemented in EU and US. In the present study, Euro NCAP Pole side impact tests were conducted to compare ES-2 and WorldSID responses. It is observed that, compared to ES-2, the chest, the abdomen, and the pelvis accelerations of WorldSID are more sensitive to the variation of the exerted external load transmitted by the deployed side air bag and the door intrusion.
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Effect of Impact-Triggered Automatic Braking in Multiple Impact Crashes

Nissan Motor Company Ltd.-Atsushi Togawa, Daisuke Murakami, Chinmoy Pal, Tomosaburo Okabe
Published 2012-04-16 by SAE International in United States
This study proposes an impact-triggered automatic braking system as a potential safety improvement based on the characteristics of the Multiple Impact Crashes (MICs). The system activates with a signal of airbag deployment in a collision to reduce the vehicle speed in the subsequent collisions. The effectiveness was estimated by an in-depth review of the National Automotive Sampling System-Crashworthiness Data System (NASS-CDS). The cases were extracted on the basis of the 3-point lap and shoulder belted occupants, incurring Maximum Abbreviated Injury Scale level 3 to 6 injuries (MAIS 3+), in the crashes occurred from 2004 to 2006, without vehicle rollover or occupant ejection, where the involved vehicles were 2000 and newer model year cars and light trucks. They were classified into three categories: (a) Single Impact Crash (SIC), (b) Multiple Impact Crash in which the Severest Impact Event occurred at the 1st collision (MIC-SIE 1) and (c) Multiple Impact Crash in which the Severest Impact Event occurred at or after the 2nd Impact Event (MIC-SIE 2+). Among the MIC-SIE 2+, we focused on the cases where…
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