Bladder and support structure for occupant weight estimation

• US 6,490,936 B1
• Filed: 05/14/1999
• Issued: 12/10/2002
• Est. Priority Date: 09/03/1997
• Status: Expired due to Term

• Current Assignee: Delphi Technologies, Inc. (BorgWarner Incorporated)
• Original Assignee: Delphi Technologies, Inc. (BorgWarner Incorporated)
• Inventors: Kaltenbacher, Phillip E II, Roe, Pamela Ann, Myers, Robert Joseph, Murphy, Morgan Daniel, Sullivan, Stuart Stites, Cobb, Gregory Allen, Oberlin, Julia Ann, Fortune, Duane Donald
• Primary Examiner(s): Raevis, Robert
• Application Number:
  US09/311,576
• Time in Patent Office: 1,306 Days
• Field of Search: 737/14, 737/13, 738/625.41, 738/625-1-8, 738/65, 177/45, 177/208, 177/209, 180/271, 180/282, 280/730.1, 280/734, 280/735, 280/742, 340/667
• US Class Current: 73/862.581
• CPC Class Codes: B60N 2/002 Seats provided with an occupancy detection means mounted therein or thereon detection means responsive to presence or absence of children B60N2/266
• CPC Class Codes: B60R 21/01516 using force or pressure sensing means
• CPC Class Codes: B60R 21/0152 using strain gauges
• CPC Class Codes: G01G 19/4142 for controlling activation of safety devices, e.g. airbag systems electrical circuits for triggering safety arrangements in case of vehicle accidents B60R21/015
• CPC Class Codes: G01G 5/04 with means for measuring the pressure imposed by the load on a liquid pressure gauges per se G01L
• CPC Class Codes: G01L 1/02 by hydraulic or pneumatic means

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. The backer board may be smooth to provide a uniform reaction surface, or contoured to increase or decrease sensitivity to weight applied on certain areas of the seating surface.

Claims

1. Apparatus for estimating the weight of an occupant of a seat in a motor vehicle, the seat having a bottom cushion supported by a frame, the apparatus comprising:

a bladder assembly sandwiched between the bottom cushion and the frame, including a fluid-filled bladder, a semi-rigid backer board interposed between the bladder and the bottom cushion or frame, and a plurality of elastic straps affixed to the bladder for securing the bladder to the backer board, the backer board being secured to the seat,

a pressure sensor coupled to an exit port of said bladder for sensing a pressure of the fluid in said bladder; and

a controller for estimating the weight of the occupant based on the sensed fluid pressure.

2. The apparatus of claim 1, wherein the backer board is disposed between the bladder and the seat frame so that the backer board, masks surface irregularities of the seat frame.

3. The apparatus of claim 2, wherein the bladder assembly includes a felt pad disposed between the backer board and the seat frame.

4. The apparatus of claim 1, wherein the backer board is disposed between the bladder and the bottom cushion so that the backer board masks surface irregularities of the bottom cushion.

5. The apparatus of claim 1, wherein the backer board is flat to provide a uniform reaction surface in contact with the bladder.

6. The apparatus of claim 1, wherein the backer board is contoured to provide a contoured reaction surface in contact with the bladder for controlling a sensitivity of the sensed fluid pressure to the occupant weight.

7. Apparatus for estimating the weight of an occupant of a seat in a motor vehicle, the seat having a bottom cushion supported by a frame, the apparatus comprising:

a bladder assembly sandwiched between the bottom cushion and the frame, including a fluid-filled bladder comprising a pattern of cells and a semi-rigid backer board interposed between the bladder and the bottom cushion or frame, the bladder being affixed to the backer board, and the backer board being contoured with axial alignment with the cells and secured to the seat;

a pressure sensor coupled to an exit port of said bladder for sensing a pressure of the fluid in said bladder; and

a controller for estimating the weight of the occupant based on the sensed fluid pressure, where the contour of the backer board controls a sensitivity of the sensed fluid pressure to the occupant weight.

8. The apparatus of claim 7, wherein the backer board is contoured to form a concave reaction surface in alignment with at least one of said cells, thereby to decrease the sensitivity of the sensed fluid pressure to occupant one cell.

9. The apparatus of claim 7, wherein the backer board is contoured to form a convex reaction surface in alignment with at least one of said cells, thereby to increase the sensitivity of the sensed fluid pressure to occupant weight acting on said at least one cell.