Seat occupant weight detection system having compensation for seat aging and usage

摘要

An improved occupant weight detection system measures the pressure in a fluid-filled bladder disposed in or under a foam seat cushion as an indication of occupant weight, and periodically adjusts the pressure vs. occupant weight relationship to compensate for changes due to aging and usage of the foam seat cushion. The system controller develops an aging adjustment value based on a measure of the cumulative aging and usage of the seat, and uses the developed adjustment value to compensate the operation of the system. The aging adjustment value is determined primarily as a function of occupant weight and time of seat occupancy, and the compensation is achieved by using the aging adjustment value to adjust either the estimated weight, or a threshold to which the measured pressure is compared for purposes of deciding if restraint deployment should be enabled.