Seat belt tension prediction system under an accelerometer mounted to the seat frame and a weight sensor

A vehicle restraint actuator control system comprises an accelerometer that generates a signal responsive to vertical acceleration of the vehicle, a force responsive sensor that generates a signal responsive to the force exerted by a mass resting on the seat, and a processor operatively coupled to the accelerometer and the force responsive sensor for controlling the actuation of a restraint actuator responsive thereto. In one embodiment, the processor calculates the average mass on the vehicle seat and predicts a force that should be exerted on the seat corresponding to a measured level of vertical acceleration assuming zero belt tension. The processor then controls the actuation of the restraint actuator responsive to a comparison of an actual force measured by the seat weight sensor with the predicted force. In another embodiment, the processor controls the actuation of the restraint actuator responsive to a ratio of a measure of seat weight divided by a measure of vertical acceleration and by the average mass.