Crash sled test based evaluation of a pre-crash seatbelt and an airbag to enhance protection of small drivers in vehicles equipped with autonomous emergency braking systems

Komeno, Fumihito; Koide, Teruhiko; Miyagawa, Toshihito; Saito, Takuhiro; Sukegawa, Yoshihiro; Ito, Daisuke; Asaoka, Michihisa; Yamada, Hiroaki

Affiliations

¹Tokai Rika Co., Ltd., Japan

²Japan Automobile Research Institute, Japan

³Toyoda Gosei Co, Ltd., Japan

Abstract

The Autonomous Emergency Braking (AEB) systems are rapidly spreading among current vehicles. In addition to the evident benefits associated with the reduction of impact speed, the AEB produces changes in the driver's posture due to inertia. Such changes need to be considered in the design process of restraint systems to optimize the protection of different occupants under all possible scenarios derived from the application of the AEB. The objective of this study is to quantify, in terms of potential reduction of injury indicators at frontal crash scenarios, two new techniques based features: 1) In-positioning function of a motorized pre-crash seatbelt (PSB) that pulls the webbing into the retractor during a pre-impact braking, 2) Enhanced interaction of an airbag with out-of-position occupants by means of a widely deployment airbag.

A series of crash sled tests were conducted with a sled system that produces controlled pre-impact braking and frontal crashes. Modified 50th percentile male and 5th percentile female Hybrid III dummies were used in order to reproduce more accurately human upper body's ability to flex forward under pre-impact braking conditions. The modifications were done at the abdomen-lumbar region and were validated against low speed sled tests with volunteers. The dummies were placed on the sled system and restrained with either a conventional seatbelt or a PSB, in combination with either a normal airbag or a widely deployment airbag. The pre-crash sled was accelerated to a speed of 64 km/h followed by a 0.8 g deceleration, prior to collision against a barrier at a speed of 48 km/h.

Less upper body forward motion during pre-impact braking was observed for the dummies with PSBs, compared to those with conventional seatbelts. This confirmed that the PSB was effective in restraining dummy's posture, thus leading to a proper restraint by the airbag and decreased injury values at the head-neck region. These observations were more pronounced for the 5th percentile female Hybrid III dummy. In addition, the widely deployment airbag contributed to the reduction of injury values.

Links

URL: http://www-nrd.nhtsa.dot.gov/pdf/esv/esv23/23ESV-000241.pdf

Cited By (1)

Year	Entry
2017	Jeong G, Park HK, Lee KS, Ko Sh, Choo H, Lee HB. Development of a driver-side airbag considering autonomous emergency braking. In: Proceedings of the 25th International Technical Conference on the Enhanced Safety of Vehicles (ESV). June 5-8, 2017; Detroit, MI.