Anthropomorphic Test Dummy; Occupant Crash Protection |
|---|
|
Ricardo Martinez
National Highway Traffic Safety Administration
February 4, 1998
[Federal Register: February 4, 1998 (Volume 63, Number 23)]
[Rules and Regulations]
[Page 5746-5748]
From the Federal Register Online via GPO Access [wais.access.gpo.gov]
[DOCID:fr04fe98-16]
=======================================================================
-----------------------------------------------------------------------
DEPARTMENT OF TRANSPORTATION
National Highway Traffic Safety Administration
49 CFR Part 572
[Docket No. NHTSA-98-3296]
RIN 2127-AF41
Anthropomorphic Test Dummy; Occupant Crash Protection
AGENCY: National Highway Traffic Safety Administration (NHTSA),
Department of Transportation.
ACTION: Final rule; technical amendment.
-----------------------------------------------------------------------
SUMMARY: In December 1996, NHTSA published a rule amending the
specifications for the Hybrid III test dummy. The dummy is specified by
the agency for use in compliance testing under its occupant protection
standard. The amendments made minor modifications in the dummy's femurs
and ankles to improve biofidelity. In response to petitions for
reconsideration, this document makes minor technical amendments and
corrections to that rule.
DATES: Effective Date: The amendments are effective March 6, 1998.
Petitions: Petitions for reconsideration must be received by March
23, 1998.
ADDRESSES: Petitions for reconsideration should refer to the docket
number of this rule and be submitted to: Administrator, National
Highway Traffic Safety Administration, 400 Seventh Street, S.W.,
Washington, D.C. 20590.
FOR FURTHER INFORMATION CONTACT: For nonlegal issues: Stan Backaitis,
Office of Crashworthiness Standards (telephone: 202-366-4912). For
legal issues: Edward Glancy, Office of the Chief Counsel (202-366-
2992). Both can be reached at the National Highway Traffic Safety
Administration, 400 Seventh St., S.W., Washington, D.C. 20590.
SUPPLEMENTARY INFORMATION: On December 26, 1996, NHTSA published in the
Federal Register (61 FR 67953) a rule amending the specifications for
the Hybrid III test dummy. The dummy is specified by the agency for use
in compliance testing under Standard No. 208, Occupant Crash
Protection. The amendments made minor modifications in the dummy's
femurs and ankles to improve biofidelity. The agency
[[Page 5747]]
explained that while the modifications may have some minimal effect on
head injury criterion (HIC), chest, and femur test data, the resulting
improvement in data quality and reliability will more than offset these
differences and make the dummy more useful in tests at the more severe
impact conditions of some research and vehicle development programs.
The American Automobile Manufacturers Association (AAMA) submitted
a petition for reconsideration of those amendments, requesting ``minor
technical corrections to the hip-femur flexion test portion of the
amendment based on discovery of some apparently inadvertent revisions
in the transcript of the final rule.'' That organization noted that the
revised dummy femur/hip joint and ankle/foot specifications were based
on a cooperative effort between the auto industry, dummy manufacturers,
and the agency. This work was conducted primarily through the Society
of Automotive Engineers (SAE) Dummy Family Task Group.
AAMA explained its requested changes as follows:
Section 572.35(c)(1) of the amendment specifies the new hip
joint femur flexion verification test. The first part of the
associated performance specification states that ``* * * the femur
rotation at 50 ft-lbf of torque will not be more than 36 deg. from
its initial horizontal orientation * * *.'' The description of this
requirement in the amendment ``preamble'' is ``* * * a load [moment]
of 50 ft-lbf cannot be exceeded before the femur rotates 36
degrees.'' Data from SAE Task Group round-robin testing * * * show
that some pelvises (especially new ones) would not meet the
``specification'' described in the preamble. This may cause some
unintended confusion. Accordingly, we recommend the following minor
change in the regulatory language for clarification, based on the
SAE Task Group data: ``* * * the femur torque at 30 degrees rotation
from its initial horizontal orientation will not be more than 70 ft-
lbf * * *.''
The second part of the section 572.35(c)(1) performance
specification states that ``* * * at 150 ft-lbf of torque [the femur
rotation] will not be less than 46 deg. or more than 52 deg.'' The
SAE Task Group agreed at its meeting of May 24, 1995 that the
flexion angle range should be approximately 41 to 48 degrees at 150
ft-lbf of applied torque, based on the round robin testing data. The
46 to 52 degree angle range corresponded to a torque of 250 ft-lbf.
The 150 ft-lbf torque with its corresponding angle range was chosen
because (1) the 250 ft-lbf torque had been shown to damage the
pelvis flesh, and (2) use of the 150 ft lbf torque would facilitate
detection of changes in the hip-femur range of motion without
significant damage to the pelvis. Thus, the 150 ft-lbf specification
with its corresponding angle range is sufficient for the purpose of
the verification test. Accordingly, consistent with the SAE Task
Group data and round-off convention, we recommend the following
minor change to the specification: ``* * * at 150 ft-lbf of torque
will not be less than 40 deg. or more than 50 deg.''
NHTSA has evaluated the minor technical changes recommended by AAMA
and concluded that they have merit. With respect to specification of
femur torque at 30 deg. of rotation, AAMA's recommendation provides a
more precise definition of when the torque measurement is to be made.
The current specification allows the torque to reach the 50 ft-lbf
value at any rotation at or before 36 deg. This torque level was
established on the basis of tests with several modified, but previously
used dummies whose femur flesh is somewhat less resistant to femur
motion than that of newly manufactured dummies. At this range of femur
rotation resistance torque is made up primarily of vinyl flesh
compression rather than direct femur to pelvis bone bumper engagement.
The slightly higher torque in the AAMA recommendation is small enough
not to have any effect on the dummy's impact response, but will allow
newly manufactured dummies to pass the calibration test specifications.
In addition, the AAMA recommendation to measure the resisting
torque at a given femur rotation will provide a more consistent
measurement of torque at a point just before the engagement with the
femur bumper occurs instead of at any rotation before the 36 degrees
are reached. Data submitted by AAMA show that torque measurement at
various rotation levels would allow more variation than needed and
would serve no purpose.
AAMA also recommended centering the femur rotation window at the
150 ft-lbf torque level by lowering the top limit from 52 deg to 50
deg. and the bottom limit from 46 deg. to 40 deg. This adjusted range
is needed to accommodate new dummies whose new and unexercised flesh
provides slightly more resistance to rotation than those dummies that
have been previously exposed to impacts.
Both requested adjustments are minor corrections of the originally
specified ranges. They have been derived and evaluated by the SAE Task
Group. NHTSA agrees they are sufficient for the purpose of verification
tests.
NHTSA also received a petition for reconsideration concerning the
hip-femur flexion test portion of the amendment from Applied Safety
Technologies Corporation, and a request for technical amendment from
Toyota. Those companies raised similar issues to those raised by AAMA,
and the amendments being made respond to their concerns.
AAMA also identified two typographical errors in the final rule.
That organization stated:
First, in the drawing list table following section 572.31(a)(3),
the date listed for the ``78051-123 arm assembly--complete (LH)'' is
``May 20, 1996'' (emphasis added). We are not aware of any changes
made to the arm assembly drawing in 1996, and believe that the
correct year is 1978 (consistent with the date listed for the right
hand arm assembly, for example). Second, paragraph (c)(2)(v) at the
end of the revised section 572.35 regulatory text in the amendment
transcript references ``paragraph (c)(3) of this section'' regarding
operating environment and temperature specifications. There is no
such paragraph in the revised section 572.35. Temperature and
humidity conditions are specified in paragraph (b)(2)(ii) of revised
section 572.35. Accordingly, this should be the reference in
paragraph (c)(2)(v) of this section.
NHTSA agrees that these were typographical errors and is correcting
them.
These minor technical amendments were not reviewed under E.O.
12866. NHTSA has considered costs and other factors associated with
these amendments, and determined that these amendments do not change
any of the conclusions in the December 1996 final rule regarding the
impacts of that final rule, including the impacts on small businesses,
manufacturers and other entities.
List of Subjects in 49 CFR Part 572
Motor vehicle safety.
In consideration of the foregoing, NHTSA amends 49 CFR part 572 as
follows:
PART 572--[AMENDED]
1. The authority citation for part 572 continues to read as
follows:
Authority: 49 U.S.C. 322, 30111, 30115, 30117 and 30166;
delegation of authority at 49 CFR 1.50.
Subpart E--Hybrid III Dummy
2. Section 572.31 is amended by revising paragraph (a)(3) to read
as follows:
Sec. 572.31 General description.
(a) * * *
(3) A General Motors Drawing No. 78051-218, revision S, titled
``Hybrid III Anthropomorphic Test Dummy,'' dated May 20, 1978, the
following component assemblies, and subordinate drawings:
[[Page 5748]]
------------------------------------------------------------------------
Drawing No. Revision
------------------------------------------------------------------------
78051-61 head assembly--complete, dated May (T)
20, 1978.
78051-90 neck assembly--complete, dated May (A)
20, 1978.
78051-89 upper torso assembly--complete, (K)
dated May 20, 1978.
78051-70 lower torso assembly--complete, (E)
dated August 20, 1996, except for drawing
No. 78051-55, ``Instrumentation Assembly--
Pelvic Accelerometer,'' dated August 2,
1979.
86-5001-001 leg assembly--complete (LH), (A)
dated March 26, 1996.
86-5001-002 leg assembly--complete (RH), (A)
dated March 26, 1996.
78051-123 arm assembly--complete (LH), dated (D)
May 20, 1978.
78051-124 arm assembly--complete (RH), dated (D)
May 20, 1978.
------------------------------------------------------------------------
* * * * *
3. Section 572.35 is amended by revising paragraphs (c)(1) and
(c)(2)(v) to read as follows:
Sec. 572.35 Limbs.
* * * * *
(c) Hip joint-femur flexion. (1) When each femur is rotated in the
flexion direction in accordance with paragraph (c)(2) of this section,
the femur torque at 30 deg. rotation from its initial horizontal
orientation will not be more than 70 ft-lbf, and at 150 ft-lbf of
torque will not be less than 40 deg. or more than 50 deg.
(2) * * *
(v) Operating environment and temperature are the same as specified
in paragraph (b)(2)(ii) of this section.
* * * * *
Issued: January 29, 1998.
Ricardo Martinez,
Administrator.
[FR Doc. 98-2645 Filed 2-3-98; 8:45 am]
BILLING CODE 4910-59-P