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Benefits of Active Head Restraints for Compliance to Rear Impact Test Requirements
Technical Paper
2007-01-0371
ISSN: 0148-7191, e-ISSN: 2688-3627
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English
Abstract
The International Insurance Whiplash Protection Group (IIWPG) rating system has driven improvements in head restraint (head restraint) geometry and the addition of a dynamic test has helped address head restraint construction parameters. FMVSS 202a Static imposes more stringent requirements on backset and stiffness and the Dynamic option relaxes the potentially uncomfortable backset requirement if angular head movement can be limited to a specified level.
These two requirements utilize different crash dummies and measurement parameters. The BioRID2 ATD (IIWPG) rewards a seat with good torso penetration to reduce neck loading. Seats with high comfort content tend to rate low. The Hybrid III-50 ATD (FMVSS) rewards limited lower torso penetration to reduce head rotation relative to the torso.
Current production seats without active head restraints (AHR) are difficult to optimize to meet both the requirements of FMVSS 202a Dynamic and earn an IIWPG rating of Good. The IIWPG rating may be degraded in order to satisfy FMVSS. However, a good AHR design can meet FMVSS 202a Dynamic and earn IIWPG Good.
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Citation
Locke, G. and Yetukuri, A., "Benefits of Active Head Restraints for Compliance to Rear Impact Test Requirements," SAE Technical Paper 2007-01-0371, 2007, https://doi.org/10.4271/2007-01-0371.Also In
Safety: Rear Impact, Rollover, Side Impact, Crashworthiness, Air Bags and Bumper Systems
Number: SP-2117; Published: 2007-04-16
Number: SP-2117; Published: 2007-04-16
References
- FMVSS 202a Final Rule December 2004
- Alliance of Automobile Manufacturers FMVSS 202a Presentation to NHTSA April 2006
- RCAR-IIWPG Seat/Head Restraint Evaluation Protocol September 2006
- Yetukuri N. Humer M. McQueen K. Smallwood D. “Head Restraint for a Seat,” United States Patent 6,880,891 Lear Corporation MI, USA April 19 2005
- Slaven J. “Durable, Energy-Absorptive, EPP/PUR Structural Composites United States Patent 5,786,394 Lear Corporation MI, USA July 28 1998
- SAE J211 Instrumentation for Impact Test, Mar95
- IIHS Seat/Head Restraint Ratings
- Thatcham Seat/Head Restraint Ratings
- Viano D.C. “Role of the Seat in Rear Crash Safety,” SAE International Warrendale, PA 2002