Patent ID: 6157880
Filing Date: 2000-12-05
Classification: B60R

Abstract:
A crash detector for activating a safety device in a vehicle in response to a side impact comprising:an accelerometer mounted on the door or on part of the monocoque shell of the vehicle adjacent the door, the accelerometer providing an acceleration signal indicative of the magnitude of the lateral acceleration to which the accelerometer is exposed and the direction of sensed acceleration relative to the centre-line of the vehicle where the acceleration signal increases with increasing inward acceleration; andmeans for processing the acceleration signal from the accelerometer to generate a control signal, said processing means altering the value of the control signal, where at least a major component of the alteration is an increase in the value of the control signal or an adjustment of the value of the control signal to make the control signal converge to at least an average of the acceleration signal from the accelerometer during periods of time in which the acceleration signal from the accelerometer indicates an inward acceleration in excess of a predetermined level of acceleration, and where at least a major component of the alteration is a reduction of the value of the control signal, by a substantially predetermined amount during successive periods of time when the acceleration signal from the accelerometer is indicative of inward acceleration which is less than said predetermined level, the control signal being passed to threshold means enabling actuation of the safety device only when the threshold has been exceeded.