Patent ID: 7606646
Filing Date: 2009-10-20
Classification: B60R

Abstract:
1. A passive safety system comprising: a single acceleration sensor that measures an acceleration of a vehicle; a determination device that includes a determination circuit having a plastic deformation pulse detection section and a severity determination section; a passive safety device that protects an occupant from injury in a vehicle accident; and an elastic deformation pulse detection section that detects an elastic deformation pulse by separating the elastic deformation pulse from an acceleration waveform produced by the acceleration sensor, the acceleration waveform produced by the acceleration sensor containing an elastic deformation pulse and a plastic deformation pulse having a high frequency higher than a frequency of the elastic deformation pulse, wherein the determination device and the passive safety device are electrically connected with the acceleration sensor and the determination device, respectively, the plastic deformation pulse detection section detects a plastic deformation pulse by separating the plastic deformation pulse from the acceleration waveform produced by the acceleration sensor, the severity determination section determines the severity of a collision based on the plastic deformation pulse detected by the plastic deformation pulse section, the passive safety device operates according to the severity, the elastic deformation pulse detection section includes a low pass filter, the elastic deformation pulse detection section separates the elastic deformation pulse by filtering the acceleration waveform with the low pass filter, the passive safety device is an airbag system having multiple inflators and one airbag that is inflated by the multiple inflators for reducing an impact of a collision on the occupant, the number of the multiple inflators to be actuated for the one airbag being determined based on the determined severity; and the determination device determines actuation of each inflator based on the severity, wherein a first inflator of the multiple inflators is actuated and then a second inflator of the multiple inflators is actuated when a predetermined period has elapsed, when the determined severity is low, the first inflator and the second inflator are simultaneously actuated to inflate the airbag when the determined severity is high, an actuation signal that actuates the first inflator is further transmitted to the second inflator by routing through an AND gate, whereby the second inflator will not be actuated before the actuation of the first inflator.