Abstract: An improved occupant detection system and method includes a fluid-filled polymeric seat cushion bladder defining multiple fluid-filled chambers corresponding to different areas of the seat cushion, with no fluid flow between such chambers. Fluid pressures in the various individual chambers are detected and processed to develop a weight estimation that is compensated for occupant position. The chambers are configured to detect occupant weight in at least forward, rearward, inboard and outboard regions of the bottom seat cushion. When the detected pressures are unevenly distributed and the pressure in the forward, rearward, inboard or outboard regions of the seat exceeds the average pressure by at least a predetermined amount, a composite pressure indicative of occupant weight is adjusted in a direction to bias the suppression status in favor of allowing restraint deployment, unless the occupant is forwardly positioned on a seat that is also forwardly positioned.

Abstract: An improved occupant detection system and method includes a fluid-filled polymeric seat cushion bladder defining multiple fluid-filled chambers corresponding to different areas of the seat cushion, with no fluid flow between such chambers. Fluid pressures in the various individual chambers are detected and processed to develop a weight estimation that is compensated for occupant position. The chambers are configured to detect occupant weight in at least forward, rearward, inboard and outboard regions of the bottom seat cushion. When the detected pressures are unevenly distributed and the pressure in the forward, rearward, inboard or outboard regions of the seat exceeds the average pressure by at least a predetermined amount, a composite pressure indicative of occupant weight is adjusted in a direction to bias the suppression status in favor of allowing restraint deployment, unless the occupant is forwardly positioned on a seat that is also forwardly positioned.

Abstract: An improved weight estimation apparatus in which an elastomeric bladder is supported on a semi-rigid backer board which is installed in a vehicle seat between the seat cushion and an underlying spring suspension. The bladder is secured onto the backer board, and the backer board is attached to the seat, enabling proper and consistent placement of the bladder relative to the seat surface. The backer board provides the reaction surface for the bladder, and masks non-uniformities of the seat structure. Additionally, the backer board will reduce or eliminate the effect of objects lying on the floor under the seat, which might otherwise pinch the bladder and produce weight estimation errors. Further, the board tends to protect the bladder from damage due to sharp objects, pinching by the suspension elements, and the effects of wires or cables routed through the seat.

Abstract: An improved weight-based occupant characterization method that can inexpensively and reliably distinguish between a child or small adult and a tightly cinched child seat. When the sensed weight is in a specified range that could be produced by a tightly cinched child seat, the system characterizes the occupant based on a detected variation in sensed weight during movement of the vehicle. If the variance of the sensed weight is below a threshold for a predetermined interval, the occupant is characterized as a child seat, since a tightly cinched seat belt severely restricts variance. If the variance exceeds the threshold for a predetermined interval, the occupant is characterized as a child or small adult. A correlative factor that can be used in distinguishing between a child seat and a child or small adult is determined by computing a slope reversal rate, or frequency, of the measured weight.

Abstract: A weight estimation apparatus for the passenger seat of a motor vehicle, in which a single bladder substantially encompassing the seat bottom is evacuated and then inflated with a known volume of air. The average pressure in the bladder is determined to estimate the passenger weight. According to a first embodiment, the apparatus continues to monitor the average pressure, and the process is re-initiated if the average pressure changes by at least a predetermined percentage. According to a second embodiment, a bleed valve allows the pressure in the bladder to slowly escape, and the apparatus monitors the rate of change in pressure as a corresponding indication of passenger weight; in this embodiment, the process of evacuating and inflating is re-initiated if the monitored change in pressure does not correspond with the estimated weight.

Abstract: An improved weight estimation apparatus includes a closed elastomeric bladder filled with fluid and installed in the foam cushion of a vehicle seat bottom, with at least one pressure sensor installed in a closed exit port of the bladder. A temperature sensor disposed in proximity to the bladder provides a temperature signal, and a controller estimates the weight of the occupant based on the temperature and pressure signals. The pressure sensor is preferably configured to sense the gage pressure--that is, the differential pressure between the fluid and atmospheric pressure--at the center of gravity of the fluid in order to provide a stable output independent of changing atmospheric pressure and changing orientation of the bladder due to vehicle pitch and roll.