Vehicle passenger restraint system

摘要

The invention is directed to a vehicle passenger restraint system having a restraint device for protecting a passenger in a vehicle. The system includes an acceleration sensor for sensing an acceleration of the vehicle, and an A/D converter for converting an output of the acceleration sensor into a digital signal indicative of the acceleration of the vehicle. A wavelet transform processor transforms the output of the A/D converter by a wavelet function into a wavelet coefficient. The wavelet function is provided on the basis of a mother wavelet function localized in time, scaled in response to a scale parameter, and shifted in response to a shift parameter indicative of a time localization. A speed variation computing unit sets a first condition when the wavelet coefficient transformed by the wavelet transform processor exceeds a predetermined value, and integrates the output of the A/D converter for a predetermined period to provide a speed variation. And, an actuator sets a second condition when the speed variation provided by the speed variation computing unit exceeds a predetermined level. Then, the actuator actuates the restraint device when both of the first and second conditions are set. The wavelet transform processor may be performed in accordance with the Infinite Impulse Response.