Two data acquisition systems, the ODAS system and the umbilical cable system, along with high-speed cameras, were used to record the data during the side-impact crash test.
ODAS system. The data from the ODAS system included 16 channels of SIDH3 data, 16 localized accelerometer channels, and three rate transducer channels. The data were filtered and digitally stored within the ODAS unit during the test. The filter was factory set at 4,000 Hz. The ADC sampling rate was factory set at 12,500 Hz. After the test, the data were down- loaded to a portable computer for analysis. The data were converted to the ASCII format, zero-bias removed, and digitally filtered at either 1,650 Hz (Society of Automotive Engineers (SAE) class 1000) for SIDH3 data, or at 300 Hz (SAE class 180) for vehicle data. Rib, spine, and pelvic data were filtered a second time using a NHTSA-supplied FIR100 filter. The class-1000 data were input into a spreadsheet for plotting. The resultant head acceleration was calculated via a spreadsheet containing the data from the triaxial accelerometer inside the SIDH3's head. The resultant data file was fed into a head injury criteria (HIC) algorithm to compute the HIC value for the crash test. The pelvic injury criteria were determined from the pelvic acceleration data. The pelvic acceleration was filtered using the FIR100 filter and the peak was located. The thoracic trauma index (TTI) was calculated from the FIR100 filtered rib and spine (T12) data. The following formula was used to compute the TTI:
TTI = [Maximum(4 rib channels) + Maximum(spine)] ÷ 2
Umbilical cable. Data collected via the umbilical cable tape recorder system was played back through an analog filter set at 1,000 Hz. The signal was then input to a data translation ADC. The data included one accelerometer channel (located at the c.g.), eight rigid pole load cell channels, an impact switch, and a monorail speed trap signal. The sample rate was set to
5,000 Hz. The digital data were converted to the ASCII format, zero-bias removed, and digitally filtered to 300 Hz (SAE class 180). The filtered data were input into a spreadsheet for plotting. Using techniques outlined in the National Cooperative Highway Research Program Report Number 350 (NCHRP Report 350)(2) the lateral occupant impact velocity (OIV) was computed.
Two square wave pulses from the lone monorail microswitch were recorded on analog tape during the crash test. The time between pulses was determined and the speed was calculated by dividing the wheel spacing (965 mm) by the time between micro- switch pulses.
High-speed film. The high-speed 16-mm film was analyzed via an NAC 160-F film motion analysis system in conjunction with a desktop personal computer. The overhead and one 90°-camera were used to acquire pertinent test data. The analyzer reduced the
