• Transactions of the Korean Society of Automotive Engineers
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• v.23 no.4
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• pp.420-427
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• 2015

This paper statistically reviewed for the USNCAP frontal crash test results carried out by NHTSA. Vehicle samples were selected on total 20 vehicles which were included on 15 vehicles for MPV&SUV and 5 Pickup. The results was summarized as followings. The performance for the driver was better than the passenger's in the average sense. There exist distinctions between the driver and the passenger on the USNCAP front test procedure, for example dummy size, seating position and airbag style. Therefore these differences originated in the statistical results. Main effect was Neck injury for crash performance on both dummies on the average value. Root cause of neck injury was different for each dummy, ie, the driver caused from Nte & Ntf, but the passenger did absolutely Nte mode. Reliability evaluated from the standard deviation was highly dependent upon chest injury on the driver and neck injury on the passenger. Restraint system was also summarized.

• Transactions of the Korean Society of Automotive Engineers
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• v.22 no.6
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• pp.1-8
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• 2014

Safety performance of a new car is evaluated through USNCAP and their results in the star rating are provided to the consumers. It is very important to obtain high score of USNCAP to appeal their performance to consumers. Therefore the car companies have made the effort to improve their car safety performance. These efforts should satisfy the demand not only to get high score but also to pass the FMVSS, NHTSA regulations on safety. Huge numbers of car crash tests have been conducted on these bases by car companies. However physical tests spend too much cost and time, as an alternative way, the simulation on the car crash could be a solution to reduce the cost and time. Therefore the simulations have been widely conducted in car industry and various researches on this have been reported. In this study, restraint system had been optimized to minimize the injury of female passenger. Belted $5^{th}%ile$ female frontal crash test was selected from various test methods of USNCAP for the study. Initial velocity of the test was 56km/h. The combination injury probability of USNCAP was selected as an objective function and the injury limit value, which was defined in FMVSS, was set to an optimization constraint. Many researches that were similar to this study had been conducted, however most of them had limitation that interaction between airbag and safety belt had not been considered. Contrary to these researches, the interaction was considered in this study.

• Transactions of the Korean Society of Automotive Engineers
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• v.20 no.5
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• pp.81-87
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• 2012

New car assessment program (NCAP) originated from USNCAP in 1979 has been implemented in several countries or markets, for instance USA, Europe, Korea, Japan, China and Australia. NCAP has contributed greatly to reduce accidental tolls. But recently, NCAP performance has no distinction between cars because manufacturer have been continuously developed to improve NCAP performance. Therefore, NHTSA announced new USNCAP protocol becoming effective from MY2011. NHTSA had carried out many NCAP tests based on the new test protocol and announced these test results. In this paper, USNCAP test results were reviewed by statistical method. This review was focused on passenger cars and frontal crash test results in order to investigate effect of changes in new NCAP protocol. There are two key changes, one is sited female dummy in passenger position, the other is enlarged to 4 scoring body regions in each dummy. Results of this review were summarized as followings. Performance in Passenger (12.5%) is lower than Driver's (50%) for number of 5 star vehicle. Neck injury criterion is dominant to NCAP star rating for both dummies in the mean sense. For standard deviation, chest deflection is showed largest value in driver dummy but neck injury criterion is showed for passenger's. DKAB and PKAB were equipped 28.1% and 6.2%, respectively. Consequently, the countermeasure for new USNCAP frontal crash test is essential to control well dummy kinematics with some safety features including KAB to reduce neck injuries.

• Transactions of the Korean Society of Automotive Engineers
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• v.21 no.2
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• pp.104-113
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• 2013

New USNCAP has been carried out by NHTSA including front and side crash from MY2011. In this paper, test results for USNCAP Side crash were reviewed by statistical analysis. This review focused on side crash test results to investigate the effect of changes from new USNCAP side crash test protocol among 30 passenger cars. These results were summarized as followings. Total number of 5 star vehicles on the front seat dummy (16 vehicles, 53.3%) was slightly smaller than the rear seat's (17 vehicles, 56.7%) in MDB test. For the ES-2re dummy, chest injury, ie maximum rib deflection contributed to 66% in the mean value of $P_{joint}$. Pelvis injury was highly dependent upon performance up to 87% in the SID-IIs dummy cited on the rear seat in average $P_{joint}$. For Pole test, pelvis injury made contribution to the average performance to 83%. For standard deviation, it showed the largest value in the same body region as the mean value for each dummy. Overall front seat performance showed 14 vehicles, 44.6% with 5 star vehicles less than each MDB or Pole test result. This result showed that performances in MDB test were different pattern to Pole test on driver position. Number of 5star vehicles for overall side NCAP performance are 18 passenger cars (60%). Curtain airbag and driver thorax airbag were equipped in all test vehicles. One vehicle is equipped with thorax airbag in the rear seat. Results from two side tests considered as reliability problem, ie the cause for large standard deviation in side crash test. Consequently, the countermeasure for new USNCAP side crash test is essential to design the effective side structures for side collision and to control well dummy kinematics with curtain and thorax airbag in order to reduce chest and pelvis injuries.

• Transactions of the Korean Society of Automotive Engineers
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• v.20 no.5
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• pp.1-7
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• 2012

Automobile airbag deployment process has been studied with MADYMO software. Based on the FMVSS208 and USNCAP(United States New Car Assessment Program) regulations, four parameters were chosen for the design improvement with reference to the 5th percentile female passenger dummy: time to fire, vent hole size, tether length and tank test pressure of inflator. Sensitivity analyses based on orthogonal arrays show that enhanced protection of small females can be achieved with improved USNCAP rating within the boundary of FMVSS 208.

• Transactions of the Korean Society of Automotive Engineers
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• v.18 no.6
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• pp.31-37
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• 2010

In proportion to increasing interest in vehicle safety, many country have regulated vehicle safety and performed NCAP(New Car Assessment Program). However vehicles which had good results in these compliance and NCAP frontal crash test have caused problems such as the fork effect and over-riding in real car-to-car accidents. To complement these issues, new frontal crash test modes using new barrier like FWDB and PDB have been developed by EEVC WG15. In this paper, FWDB frontal crash test was performed and the result was compared with the full frontal crash test using the rigid wall in order to comprehend the characteristic of FWDB. The results of FWDB test were compared with one of USNCAP and KNCAP. Using USNCAP data, vehicle performance like deformation and wall force were studied. A comparative study of dummy injuries was made by using KNCAP result. The results showed that vehicle performance of FWDB test like displacement and effective acceleration was similar in spite of absorbing energy of FWDB due to the greater vehicle deformation of rigid wall test. In FWDB test, driver dummy head bottomed out but most of injuries were superior to the injury of rigid wall test.

• Journal of Auto-vehicle Safety Association
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• v.12 no.4
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• pp.31-38
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• 2020

This study is to develop the prediction model for the HIC15 in frontal vehicle crash tests. The 28 frontal impact test results of the MY2019 and MY2020 USNCAP are utilized. The metrics for evaluating the crash pulse severity such as moving average acceleration, Restraint Quotient (RQ) and ride-down efficiency are reviewed to find out whether the metrics can predict the HIC15. It is observed that the R² values based on the linear regression of all pairs between the existing metrics and the occupant injuries such as the HIC15, 3 ms chest g's and chest deflection are very low. In this study, using the vehicle crash pulses, the linear regression model for estimating the HIC15 is developed. The vehicle crash pulse is splitted seven 10 ms intervals in 70 ms after impact for extracting the average accelerations in each intervals. The prediction model can predict effectively not only the HIC15 but also the maximum head g's, chest deflection and 3 ms chest g's of 13 vehicles out of 28 vehicles.

• Journal of Auto-vehicle Safety Association
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• v.14 no.1
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• pp.62-67
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• 2022

This study is to construct the simple estimating model for the HIC15 of the driver dummy using the frontal impact test results. Test results of 9 vehicles of Hyundai Sonata from the MY2002~MY2020 USNCAP are utilized for constructing the linear regression model. The average accelerations extracted from the vehicle crash pulses are handled as the main factors. The average accelerations of 10 ms interval within 0~100 ms are calculated from the crash pulse data of 9 vehicles. The present estimating model of the HIC15 using the average accelerations of 10 ms interval in the 0~80 ms range shows good agreement with the tested value within 2.4% maximum error.

• Transactions of the Korean Society of Automotive Engineers
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• v.20 no.4
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• pp.10-15
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• 2012

The design of automobile occupant seat belt system has been studied by using MADYMO. Based on the FMVSS 208 (Federal Motor Vehicle Safety Standards 208) and the USNCAP (United States New Car Assessment Program) regulations, seat belt design parameters were chosen for the design improvement to the 5th percentile female dummy: limit force of load limiter, time to fire of shoulder belt, inlet length of shoulder belt, inlet length of lap belt. The design of experiment method was employed to optimize the design parameters of passenger seat belt. Range of injury probability due to the change of H-point position was estimated by the simulation.

• Journal of Auto-vehicle Safety Association
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• v.15 no.1
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• pp.55-62
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• 2023

In this study, a chest deflection is predicted by introducing a deep learning technique with the results of the frontal impact of the USNCAP conducted for 110 car models from MY2018 to MY2020. The 120 data are divided into training data and test data, and the training data is divided into training data and validation data to determine the hyperparameters. In this process, the deceleration data of each vehicle is averaged in units of 10 ms from crash pulses measured up to 100 ms. The performance of the deep learning model is measured by the indices of the mean squared error and the mean absolute error on the test data. A DNN (Deep Neural Network) model can give different predictions for the same hyperparameter values at every run. Considering this, the mean and standard deviation of the MSE (Mean Squared Error) and the MAE (Mean Absolute Error) are calculated. In addition, the deep learning model performance according to the inclusion of CVW (Curb Vehicle Weight) is also reviewed.