Matthew Maltese: 2002 SAE Govt/Industry meeting


SLIDE 1:
SIDE IMPACT DUMMY BIOFIDELITY



SLIDE 2:
OVERVIEW:
- what is biofidelity?
- impact testing
- translating test data into a biofidelity score
- biofidelity of various side impact dummies
- conclusions


SLIDE 3:
WHAT IS BIOFIDELITY
A crash test dummy should:
- load the crash environment like a human would
a side impact dummy should impart human-like force-area-time history upon the vehicle environment

- predict human injury consequences
a side impact dummy should reporduce the necessary internal kinematic and kinetic measurements to accurately predict injury


SLIDEs 4-5:
BIOFIDELITY EVALUATION PROCESS
- test the dummy and human surrogate in an environment similar to the crash
- compare quantitatively the response of the human and dummy
- combine the quantitative response comparison from each test into a meaningful score



SLIDE 6:
BIOFIDELITY EVALUATION PROCESS
 Impact Testing


SLIDE 7:
NHTSA BIOFIDELITY IMPACT TESTS
- Biofidelity tests are conducted on both dummies and human surrogates iun a variety of test conditions

- Tests include
  * whole-body sled tests to quantify the performance of the torso and pelvis as a system
  * pendulum tests to the thorax and shoulder
  * neck tests to ensure the head is corectly positioned for a head strike.
  * head drop tests to quantify the response of the head exposed to blunt impact


SLIDE 8:
NHTSA BIOFIDELITY IMPACT TESTS
<diagrams>
- head drop tests
- neck test
- thoracx tests
- sled tests


SLIDE 9:
BIOFIDELITY EVALUATION PROCESS
- Quantitative Response Comparison


SLIDE 10:
DUMMY-TO-HUMAN COMPARISON
- Human surrogate and dummy response signals are overlayed

- the dummy response (D) surrogate mean, and standard deviation (SD) are then combined to quantify (R) how well the dummy matches the cadaver


SLIDES 11-13:
addendum plate force (newtons)
padded 8.9 m/s flat wall sled test


SLIDE 14:
BIOFIDELITY EVALUATION PROCESS
Biofidelity Score Calculation


SLIDE 15:
TEST CONDITION WEIGHTS
- each R score is weighted according to its test condition
- the test condition weights quantify
- two factors influence the weights
  * the number of human surrogate test subjects used to develop the corridor.
  * the degree to which a particular test condition matches the real-world crash environment

SLIDE 16:
BIOFIDELITY EVALUATION PROCESS
Score


SLIDE 17:
BIOFIDELITY SCORES
Two scores are calculated:
 - environmental biofidelity rank  = average of the weighted R values from load wall and pendulum forces, as well as head/neck displacement and angle

 - injury criteria fidelity rank = average of the weighted R values from the signals used to calculate the injury criteria for a particular body region


SLIDE 18:
RATING DUMMY BIOFIDELITY

0 <= B <= 1	EXCELLENT
1 < B <= 2	GOOD
2 < B <= 3	MODERATE
3 < B		POOR	

smaller = better


SLIDE 19:
DUMMY SCORES		<ES-2>		<SID/H3>	<WSIDp>
	(smaller/better)
IMPACT BIOFIDELITY
  overall		<3.4>		<3.6>		<2.5>
  head/neck		<3.7>		<1.0>		<2.1>
  shoulder		<1.2>		<5.6>		<2.1>
  thorax 		<5.4>		<6.3>		<3.1>
  abdomen		<3.6>		<3.5>		<2.5>
  pelvis 		<2.6>		<3.6>		<3.4>

INJURY CRITERIA FIDELITY
  head			<0.6>		<0.6>		<0.4>
  thorax 		<1.1>		<1.1>		<1.1>
  abdomen		<3.6>		<N/A>		<1.3>
  pelvis 		<1.8>		<1.8>		<1.9>


SLIDE 19:
CONCLUSIONS
- In terms of the biofidelity of the dummy-to-vehicle interaction, 
  * the SID/H3 is less biofidelic than the ES-2 and
  * the WorldSID Prototype is more biofidelic than both the SID/H3 and the ES-2

- In terms of the biofidelity of the measurements on the dummy required to predict injury, 
  * the head and thoract of SID/H3, ES-2 and WorldSID prototype were equally biofidelic,
  * the abdomen of the WorldSID prototype is more biofidelic than the ES-2, and the SID has no abdominal injury detection capability, and
  * the pelvis of the SID/H3, ES-2 and WorldSID prototype have roughly the same biofidelity.


SLIDE 21:
Thank You