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Evaluation of Harness Tightening Procedures for Child Restraint System (CRS) Sled Testing
ISSN: 0148-7191, e-ISSN: 2688-3627
Published April 2, 2019 by SAE International in United States
This content contains downloadable datasetsAnnotation ability available
Sled testing procedures should reflect a rigorous level of repeatability across trials and reproducibility across testing facilities. Currently, different testing facilities use various methods to set the harness tension for child restraint system (CRS) sled tests. The objective of this study is to identify which harness tightening procedure(s) produce tensions within a reasonable target range while showing adequate reproducibility, repeatability, and ease-of-use. Five harness tightening procedures were selected: A) FMVSS 213 procedure, B) a 3-prong tension gauge, C) ECE R44/R129 procedure, D) two finger method, and E) pinch test. Two CRS models were instrumented with a tension load cell in the harness system. Seven sled room operators were recruited to perform each of the five harness tightening procedures for ten repetitions apiece on both instrumented CRS using a Hybrid III 3-year-old. The static harness tension measured by the load cell was recorded after each procedure was completed. Data were analyzed for mean, variance, reproducibility, and repeatability. Operator feedback surveys were used to quantify ease-of-use.
The ECE R44/R129 procedure produced harness tensions which were quite low. The two finger procedure produced the highest tensions while the 3-prong tension gauge, pinch test, and FMVSS 213 procedures produced mid-level tensions. Poor repeatability was apparent for all five harness tightening procedures. The FMVSS 213 method ranked lowest for ease-of-use. Operators preferred using the 3-prong gauge, two finger method, and pinch test.
The load cell readings were sensitive to the order and direction in which the operators adjusted the harness components. High amounts of friction within the harness might prevent it from acting as a homogeneous, continuous system. Sequential tightening of the various sections of harness and/or monitoring the tension at multiple locations might be valuable.
CitationMansfield, J., Baker, G., and Bolte, J., "Evaluation of Harness Tightening Procedures for Child Restraint System (CRS) Sled Testing," SAE Technical Paper 2019-01-0617, 2019, https://doi.org/10.4271/2019-01-0617.
Data Sets - Support Documents
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- Hummel, T., Langwieder, K., Finkbeiner, F., and Hell, W., “Injury Risks, Misuse Rates and the Effect of Misuse Depending on the Kind of Child Restraint System,” SAE Technical Paper 97330, 1997, doi:10.4271/973309.
- Lalande, S., Legault, F., and Pedder, J., “Relative Degradation of Safety to Children when Automotive Restraint Systems are Misused,” in Proceedings of the 18th Enhanced Safety of Vehicles Conference Paper No. 85, Nagoya, Japan, 2003.
- Arbogast, K., Cornejo, R., Kallan, M., Winston, F. et al., “Injuries to Children in Forward Facing Child Restraints,” Ann Proc Assoc Adv Automot Med 46:213-230, 2002.
- Arbogast, K., Ghati, Y., Menon, R., Tylko, S. et al., “Field Investigation of Child Restraints in Side Impact Crashes,” Traffic Inj Prev 6(4):351-360, 2005, doi:10.1080/15389580500255831.
- Skjerven-Martinsen, M., Naess, P., Hansen, T., Rognum, T. et al., “In-Depth Evaluation of Real-World Car Collisions: Fatal and Severe Injuries in Children Are Predominantly Caused by Restraint Errors and Unstrapped Cargo,” Traffic Inj Prev 12(5):491-499, 2011, doi:10.1080/15389588.2011.596868.
- National Highway Traffic Safety Administration (NHTSA), US Department of Transportation, “Laboratory Test Procedure for FMVSS 213 Child Restraint Systems,” TP-213-10, February 16, 2014.
- United Nations Economic Commission for Europe (UNECE), Regulation No. 129, Rev. 2, Add. 128, August 7, 2013.
- National Highway Traffic Safety Administration (NHTSA), “National Child Passenger Safety Certification Training Program, Technician Guide,” March 2014.