DETECTION OF COLLISION BY COMBINATION OF ACCELEROMETER AND HIGH-FREQUENCY PRESSURE TRANSDUCER

摘要

PURPOSE: To make reliable sensing of the half period of the strength of collision, the colliding direction, and initial speed change by the combined use of a low frequency accelerometer and a plurality of high frequency sensors. CONSTITUTION: A high-frequency detection circuit 14 has a series of high-frequency pressure converters 16 for detecting a high-frequency signal, resulting from the deformation of metals during a collision, and each converter 16 severally has BPF 18. Each converter 16 detects the collision in either of the frequency bands different in a certain fixed number, so as to more accurately express the violence of the collision, and sends a detection signal through an A/D converter 20 to a microprocessor 22. The processor 22 judges whether the development of an airbag is necessary or not from this signal and signals sent from a low frequency accelerometer circuit 12 about the directional information of the collision and the deceleration information of a vehicle, and gives necessary signals to an airbag-activating circuit 24. In this case, a passenger restraining device 10 can be formed near the airbag as a single assembled body in a section for the passenger.