PURPOSE: To certainly detect only collision by mounting a mechanism extracting an waveform characteristic from the output signal of the acceleration sensor of a vehicle and judging whether collision is generated from said characteristic.
CONSTITUTION: The detection signal of an acceleration sensor 1 is digitalized by an A/D converter 3 while the noise thereof is removed by a low-pass filter 2 to be outputted to an offset integrating operator 4 and a collision waveform characteristic extraction part 5. An offset value is set and integrated by said integrating operator 4 and the integrated value is compared with a reference value by a comparator 6 to sent the comparison result to a collision judging part 7 while a frequency component is extracted by said extraction part 5 to be sent to a collision waveform similarity operation part 8 and, when it is judged that there is similarity in a standard pattern and the extracted waveform in the operation part 8, the judgment result is outputted to a comparator 9 to be compared with the output from the operation part 8 and the comparison result is sent to the judging part 7. The judging part 7 judges collision when the signals of both comparators 6, 9 are simultaneously inputted. By this method, collision can be certainly judged.
HIRAO MANABU
KATAOKA NORIAKI
| US4842301A | 1989-06-27 |