Download T/HIS 9.4 user manual

User manual Version 9.4, November 2009
T/HIS
D.4 Standard SAE Filter Options
Channel Filter Classes 60, 180, 600 and 1000 are Butterworth filters with the following parameters:
Filter Class
Cut-off Frequency
Order
60
100Hz
2
180
300Hz
2
600
1000Hz
2
1000
1650Hz
2
The gain characteristics are compared with the limits given in BS AU228 in the following four figures.
D.5 Standard FIR filter option
The FIR filter (Finite Impulse Response) is specified by NHTSA. It is used for filtering thoracic accelerations from side
impact dummies; the filtered accelerations are then used in calculation of TTI (Thoracic Trauma Index). Its
characteristics are:
•
A passband frequency of 100Hz.
•
A stopband frequency of 189Hz.
•
A stopband gain of -50dB.
•
A passband ripple of 0.0225dB.
It is based on a standard Fortran programme available from NHTSA.
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