Whiplash Testing Protocol - Euro NCAP

Appendix IV
1. Definitions
Version 3.1
June 2011
Sled Pulse Specifications
1.1. Offset adjust the accelerometer
In order to make sure that there is no initial acceleration, which result in a non-zero velocity
profile, it is required to offset adjust the acceleration signal. It is assumed that this step is a
standard procedure for the participating laboratories and shall therefore not be discussed
into further detail.
1.2. Filter with CFC 60
To ensure that low level noise does not influence the results the acceleration signal is
filtered with a CFC 60 filter („endpoints‟-method in Diadem). The CFC 60 filter is used
according to SAE J211, for sled acceleration signals.
1.3. Definition of T0
T0 is defined as the time before the CFC60 filtered sled acceleration reaches 1.0g. The
relevant times for the low, medium and high pulses are 4.6ms, 5.8ms and 3.7ms
respectively.
1.4. Definition of T1
T1 is defined as the time when the sled acceleration for the first time is > 1g. Both the
initial onset of the pulse and specific low acceleration disturbances (< 0.5g) heavily
influence the behaviour at the start of the pulse. For that reason, it is in practice not possible
to identify the actual start of the pulse. Acceleration levels higher than 1g however are
unmistakably a direct result of the pulse on the sled. As such, the moment in time when the
sled acceleration crosses 1g can be uniquely and easily be found.
1.5. Definition of TEND
TEND is defined as the time when the sled acceleration for the first time is < 0g.
1.6. Definition of dT
dT is defined as the time span between TEND and T0,
dT = TEND - T0
1.7. Definition of dV
dV is defined as the difference between the maximum and minimum sled velocity between
T0 and TEND.
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