| 摘要 |
PURPOSE:To certainly detect the collision of a vehicle. CONSTITUTION:The distance from a forward obstacle and the timewise change rate thereof are calculated by a distance sensor 11 and a differentiation circuit 20 differentiating the detection value of the distance sensor 11 and it is judged whether daid distance becomes 0 within a time T. When the distance becomes 0 within the time T, a collision inevitable signal is outputted. Only when collision is actually detected when said signal is outputted, a collision signal (air bag operation signal) is outputted. The collision of a vehicle can be immediately and certainly detected and the inflator of an air bag device is operated immediately after the collision of the vehicle can be operated. The capacity of the inflator can be reduced and the necessary strength of an air bag can be reduced. |
