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Abstract
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27th International Technical Conference on the Enhanced Safety of Vehicles (ESV): Enhanced and Equitable Vehicle Safety for All: Toward the Next 50 Years
https://www-esv.nhtsa.dot.gov/Proceedings/27/27ESV-000058.pdf
Objective: Vehicles are expected to meet standard crash tests requirements for both structural and occupant performance specified by governments and consumer advocacy groups. These tests command a specific ATD size in well-defined seating position with a certain impact speed of the vehicle or a moving barrier. In these standardized tests, typically, the 5th percentile female dummy and 50th percentile male dummy are specified, and the vehicle's occupant restraint system is optimized simultaneously for these dummies. With adaptive restraint system, the system can be optimized independently for 5th percentile, 50th percentile, and 95th dummies to maximize the protection. The objective of this research is to establish a methodology to classify diverse population such that a best set of optimized restraint systems derived from dummies can be tailored to an individual of any size. Methods: A validated finite element vehicle sled model was selected for this study. US-NCAP standardized crash condition was simulated to optimize three vehicle restraint system designs for HIII small female, midsize male, and large size male independently. Twelve design variables of the airbag, seatbelt systems, and steering column were selected for such optimization. Fifty female and fifty male human body models (HBMs) morphed from GHBMC M50-OS model were used to represent diverse driver populations with various age, stature and BMI of the US population. Automated process was developed for positioning the HBMs into the driver position for occupant safety simulations. The three optimized restraint systems developed for small female, midsize male, and large size male dummies independently, were then applied to each of the 100 HBMs. To evaluate the safety performance of the three optimized designs on each of the HBM, the joint probability of injury for each of the simulations were calculated. Results: Three sets of restraint systems were optimized for the Hybrid III 5th, 50th, and 95th by minimizing the occupant injury risk in a regulated 35mph impact condition. Each of the three sets of restraint systems was used to assess the safety performances of each of the 100 HBM's. Based on the best fit restraint system selected for each of the 100HBM's, the boundaries dividing the diverse population are drawn. The population classification methodology is established for a vehicle with adaptive restraint system. Discussions and Limitations: The vehicle pulse used in this study was NCAP 35mph rigid barrier crash pulse only and the occupant classification boundary based on this pulse may change for lower speed or different types of barriers impacts. The 100HBMs were developed based on simplified GHBMC model and the classification boundary could be different if detailed GHBMC models were used to morph the 100 HBMs. Conclusions: The processes discussed in this study show the potential of classifying a diverse population based on the best-fit restraint system from the three systems which were optimized originally for the dummy sizes: 5th female, 50th male, and 95th male.
Language: en |