Method and apparatus for determining time to fire an occupant restraint system using occupant sensor inputs

A method for sensing the occurrence of a vehicle crash in a vehicle having an occupant restraint system operatively connected with a crash sensor having an accelerometer which produces an accelerometer signal, and with an occupant position sensor which produces a position signal, wherein the crash sensor includes an adjustable filter, the method comprising:

• calculating an estimated occupant displacement by integrating the accelerometer signal twice;
• comparing said estimated occupant displacement to the position signal;
• and
• adjusting the adjustable filter based upon said comparing step so that said estimated occupant displacement closely correlates with the position signal, thereby optimizing control of the occupant restraint system.

A method for providing a passenger restraint actuation signal in a vehicle which includes a crash sensor having an accelerometer which produces an accelerometer signal, and an occupant position sensor which produces a position signal, wherein the crash sensor includes an adjustable filter, the method comprising:

• calculating an estimated occupant displacement by integrating the accelerometer signal twice;
• comparing said estimated occupant displacement to the position signal to determine whether a particular crash event is of long duration;
• and
• adjusting the adjustable filter to optimize early firing time of the occupant restraint system.