| 摘要 |
PURPOSE: To provide a device and a method properly operating a body restraint device in compliance with a specified crash condition by specifying a crash condition in case of a vehicle crash. CONSTITUTION: This apparatus is provided with an accelerometer assembly 22 generating a vibration electric signal for a time domain possessing a frequency constituent showing a vehicle crash condition, and the acceleration signal from this assembly is converted into a digital signal by means of an A/D converter 102, and then, Fourier transformation is carried out by means of a digital transformation processor 110 so as to transform the digital signal of the corresponding time domain into a frequency domain signal over at least two time intervals and stored in a memory 124. By means of a microcomputer 120, the amplitudes of all the frequency bins over the entire frequency spectrum for each frequency domain signal are summed to provide a value corresponding to the integral of the amplitudes of all the frequency bins over the entire frequency spectrum for the associated frequency domain signal, and the integral values of the frequency domain signals are summed. A microcomputer monitors the sum of these integral values and actuates an occupant restraint device by igniting a squib 144 when excess of the sum over a predetermined threshold is determined, and therefore, occurrence of a specific type vehicle crash is detected. |
