A monorail speed trap, transducers attached to the pickup truck and SIDH3, and rigid pole load cells were used to collect data during the broadside crash test. The output from the transducers, load cells, and speed trap were recorded via two data acquisition systems, the ODAS III onboard system and an umbilical cable/FM tape recorder system. Table 4 summarizes the channel assignments for each data system.
Onboard data acquisition system (ODAS)
The ODAS III system collected 35 channels of data. The data were from accelerometers, a triaxial rate transducer, and 16 SIDH3 channels. The output from the sensors was prefiltered, digitally sampled, and digitally stored within the ODAS III units mounted directly to the test vehicle outside the occupant compartment in the truck bed. The ODAS III units are factory set with a 4,000 Hz analog prefilter and a digital sampling rate of 12,500 Hz.
The FOIL umbilical cable system utilizes a 90-m cable between the vehicle transducers, rigid pole load cells, or other sensors and a rack of 10 signal conditioning amplifiers. The output from the amplifiers was recorded on 25-mm magnetic tape via a Honeywell 5600E FM tape recorder. After the test, the tape is played back through anti-aliasing filters, then input to a data translation analog-to-digital converter. The sample rate was set to 5,000 Hz. The tape recorded signals from 12 transducers. The system recorded outputs from one c.g. accelerometer, one displacement transducer, eight rigid pole load cells, the monorail speed trap, and an impact contact switch to electronically mark first contact between the vehicle and the pole. The speed trap signals and the impact contact switch were not conditioned before being recorded.
The speed trap consisted of a single microswitch mounted to the monorail 4.2 m from the pole. The wheels from the main side-impact carriage trip the switch as the vehicle passes over the speed trap. The distance between the two main carriage wheels was 965 mm.
