Vehicle occupant weight estimation apparatus having controlled volume seat bladder
First Claim
1. Apparatus for estimating the weight of an occupant of a seat in a motor vehicle, the seat having a foam cushion bottom, the apparatus comprising:
- an elastomeric bladder substantially encompassing a seating area of the foam cushion bottom;
a pump coupled to the bladder;
a pressure sensor for developing a pressure signal corresponding to the pressure in the bladder; and
a controller for initiating a weight estimation sequence of operations, including (1) operating the pump to substantially evacuate the bladder, (2) operating the pump to inflate the bladder with a predetermined volume of fluid, (3) monitoring the pressure signal, (4) determining an average value of the pressure signal after the bladder has been inflated, and (5) estimating the weight of the occupant based on the determined average pressure value, wherein subsequent to the weight estimation sequence of operations, the controller periodically determines average values of the pressure signal after the bladder has been inflated, and re-initiates the weight estimation sequence of operations when a periodically determined average pressure value deviates from the average pressure value on which the estimated weight was based by at least a predetermined amount.
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Accused Products
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. The sides of the bladder may be pleated to permit the bladder to expand under the weight of an occupant without stretching the bladder, and thereby affecting the average pressure. A temperature sensor may be disposed in proximity to the bladder provides a temperature signal for compensating the weight estimation for temperature variations. Also, the pressure sensor may be configured to sense the gage pressure--that is, the differential pressure between the bladder pressure and atmospheric pressure; alternatively, the pressure sensor may be configured to detect absolute pressure, and a second absolute pressure sensor responsive to atmospheric pressure may be used to compensate for changes in atmospheric pressure.
73 Citations
10 Claims
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1. Apparatus for estimating the weight of an occupant of a seat in a motor vehicle, the seat having a foam cushion bottom, the apparatus comprising:
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an elastomeric bladder substantially encompassing a seating area of the foam cushion bottom; a pump coupled to the bladder; a pressure sensor for developing a pressure signal corresponding to the pressure in the bladder; and a controller for initiating a weight estimation sequence of operations, including (1) operating the pump to substantially evacuate the bladder, (2) operating the pump to inflate the bladder with a predetermined volume of fluid, (3) monitoring the pressure signal, (4) determining an average value of the pressure signal after the bladder has been inflated, and (5) estimating the weight of the occupant based on the determined average pressure value, wherein subsequent to the weight estimation sequence of operations, the controller periodically determines average values of the pressure signal after the bladder has been inflated, and re-initiates the weight estimation sequence of operations when a periodically determined average pressure value deviates from the average pressure value on which the estimated weight was based by at least a predetermined amount. - View Dependent Claims (2, 3, 4, 5, 6, 7)
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8. Apparatus for estimating the weight of an occupant of a seat in a motor vehicle, the seat having a foam cushion bottom, the apparatus comprising:
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an elastomeric bladder substantially encompassing a seating area of the foam cushion bottom; a pump coupled to the bladder; a pressure sensor for developing a pressure signal corresponding to the pressure in the bladder; a controller for initiating a weight estimation sequence of operations, including (1) operating the pump to substantially evacuate the bladder, (2) operating the pump to inflate the bladder with a predetermined volume of fluid, (3) monitoring the pressure signal, (4) determining an average value of the pressure signal after the bladder has been inflated, and (5) estimating the weight of the occupant based on the determined average pressure value; a bleed valve for allowing the pressure in the bladder to slowly escape subsequent to the weight estimation sequence of operations; and wherein the controller monitors a rate of change in said pressure signal, determines a secondary estimation of occupant weight based on said monitored rate of change, and re-initiates the weight estimation sequence of operations when the secondary estimation of weight deviates from the estimated weight by at least a predetermined amount. - View Dependent Claims (9, 10)
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Specification