This content is not included in your SAE MOBILUS subscription, or you are not logged in.
Use of Instrumented Earplugs to Measure Driver Head Accelerations
ISSN: 0148-7191, e-ISSN: 2688-3627
Published December 02, 2002 by SAE International in United States
Annotation ability available
This paper reports on cooperative research between the Air Force Research Laboratory (AFRL) and motorsports to establish a relationship between multi-axis impact acceleration and injury for improving pilot/driver protection concepts Problem: The particular problem addressed by this paper is to establish how well head accelerations recorded by accelerometers mounted in molded earplugs inserted in manikin ears correlate with head accelerations measured by internal accelerometers. Method: Very small (0.4 gm) Endevco model 7269-500 tri-axial accelerometers were mounted in molded earplugs. In the laboratory, the earplugs were inserted into artificial ears glued to a Hybrid III manikin head. The headform was covered with artificial “skin” shaped to match a 3D scan of a human head. The headform, wore an instrumented (6 DOF) race helmet (reported on last conference), was instrumented internally with accelerometers (6 DOF), was attached to a sled and dropped on a Monterey Vertical Impact Device at from 12.5 G to 100 G in various (x, y, z, Rx, Ry, Rz) directions. Results: In 80 drops there was a progressive increase in acceleration recorded at the sled, then the base of the neck and finally the earplug. These differences were most probably due to the behavior of the headform mounting structure. Earplugs mounted directly on the sled replicated the sled acceleration within 5%. Conclusion: Since these results represent the behavior of a mechanical head and “rubber” ears, they need to be confirmed by using human volunteers up to 10 G (safe level) accelerations. Application to Racing: By monitoring drivers during crashes, it should be possible to calculate neck loads for correlation with injury data collected by medical personnel, and to revise impact tolerance criteria pertinent to racing, military and commercial crash protection.
CitationKnox, T., "Use of Instrumented Earplugs to Measure Driver Head Accelerations," SAE Technical Paper 2002-01-3303, 2002, https://doi.org/10.4271/2002-01-3303.
- Ensor, 1970 Calibration by the Comparison Method
- Dyncorp Test Configuration and Data Acquisition System for the Race Helmet Instrumentation Study (Race Hat Study), Contract F3301-96-DJ001 March 2001
- Melvin, John W. Biomechanical Analysis of Indy Race Car Crashes 42 Stapp Car Crash Conference Tempe, AZ November 2-4 1998 SAE Technical Papers 983161
- Hill, Doug, Knox, Ted, Crockett, Dave. Monitoring Race Car Drivers Using Helmet and Head-Mounted Sensors. Papers 00MSV-46 (reprint 2000-01-3557). SAE Motorsports Exhibition and Conference 2000
- Knox, Ted et al Monitoring Race Car Drivers Using Helmet and Head-Mounted Sensors ICMS Conference 2001
- Knox, Ted, Olvey, Stephan E. Hill, Douglas, Strategies for Monitoring Driver Head Motion: A Status Report ICMS-FIA Conference Miami, FL Feb