Patent ID: 6850825
Filing Date: 2005-02-01
Classification: B60R

Abstract:
1. A method of determining whether to allow or suppress deployment of a vehicular inflatable restraint for a vehicle occupant based at least in part on an output signal of a sensor responsive to occupant weight applied to a vehicle seat, the method comprising the steps of: comparing a filtered version of said output signal to a threshold having a default value corresponding to a predetermined occupant weight under a given set of conditions; measuring a vertical acceleration of the vehicle; sampling output signal values and computing an average of the sampled values; identifying sampled output signal values that are within a specified percentage of said average; computing a first variance of the identified output signal values; computing a second variance of the measured vertical acceleration; determining a free mass of the vehicle occupant according to a ratio of the first variance and the second variance; establishing a predetermined range of free mass values corresponding to an average weight occupant; adjusting said threshold below said default value when the determined value of said free mass is above a the predetermined range of free mass values; adjusting said threshold above said default value when the determined value of said free mass is below the predetermined range of free mass values; maintaining a current value of said threshold when said free mass is within said predetermined range of free mass values; and allowing deployment of said restraint when the filtered version of said output signal is above said threshold, and suppressing deployment of said restraint when the filtered version of said output signal is below said threshold.