Weight Determining Systems and Methods for Vehicular Seats

• US 20070085697A1
• Filed: 06/12/2006
• Published: 04/19/2007
• Est. Priority Date: 06/07/1995
• Status: Active Grant

• Current Assignee: American Vehicular Sciences LLC (Acacia Research Corporation)
• Original Assignee: Automotive Technologies International Incorporated
• Inventors: Breed, David
• Granted Patent: US 7,523,803 B2
• Time in Patent Office: Days
• US Class Current: 340/825.720
• 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: H04Q 9/00 Arrangements in telecontrol or telemetry systems for selectively calling a substation from a main station, in which substation desired apparatus is selected for applying a control signal thereto or for obtaining measured values therefrom

Abstract

Vehicular seat including a weight determining system for obtaining an indication of the weight of an occupying item in the seat includes a seat support structure, a cushion arranged on the seat support structure, the cushion having an upper surface over which the occupying item is situated during occupancy of the seat and being arranged to deflect downward during occupant of the seat, and a sensor system arranged to sense the downward deflection of the cushion and convert the downward deflection into an indication of the weight of the occupying item. The sensor system may include an elongate cable, a cable support retaining a first end of the cable and a displacement sensor arranged at a second end of the cable for measuring linear variations of the cable which are convertible into the indication of the weight of the occupying item.

Claims

1. A vehicular seat including a weight determining system for obtaining an indication of the weight of an occupying item in the seat, comprising:

a seat support structure;

a cushion arranged on said seat support structure, said cushion having an upper surface over which the occupying item is situated during occupancy of the seat, said cushion being arranged to deflect downward during occupant of the seat; and

a sensor system arranged to sense the downward deflection of said cushion and convert the downward deflection into an indication of the weight of the occupying item.

2. The seat of claim 1, wherein said sensor system comprises an elongate cable, a cable support retaining a first end of said cable and a displacement sensor arranged at a second end of said cable for measuring linear variations of said cable which are convertible into the indication of the weight of the occupying item.

3. The seat of claim 2, wherein said cable is arranged to stretch axially as a function of the weight of the occupying item and said displacement sensor is arranged to determine the axial stretching of said cable.

4. The seat of claim 2, wherein said displacement sensor comprises a rod connected to said cable and arranged to move upon axial stretching of said cable as a function of the weight of the occupying item, said displacement sensor being arranged to measure the movement of said rod.

5. The seat of claim 4, wherein said displacement sensor further comprises a cylinder having a channel in which said rod is movable, and a spring biased to return said rod to a rest position.

6. The seat of claim 5, wherein said cylinder includes first and second windings of a linear variable differential transformer which are axially spaced apart from one another, movement of said rod being measured by the amount of coupling between said first and second windings,

7. The seat of claim 2, wherein said displacement sensor further comprises biasing means for biasing said cable into a non-displaced position in which it assumes in the absence of an occupying item on the seat.

8. The seat of claim 2, further comprising supports arranged at opposed edges of said cushion, said cable support and said displacement sensor being coupled to a respective one of said supports.

9. The seat of claim 2, wherein said displacement sensor is selected from a group consisting of a linear rheostat, a linear variable differential transformer and a linear variable capacitor.

10. The seat of claim 2, wherein said cushion comprises a foam layer and a spring system arranged under said foam layer, said cable being arranged under said spring system such that deflection of said spring system causes axial stretching of said cable.

11. The seat of claim 1, wherein said cushion comprises a foam layer and a spring system arranged under said foam layer and which is in contact with said sensor system.

12. The seat of claim 1, further comprising supports arranged at opposed edges of said cushion, said sensor system being supported from said supports.

13. The seat of claim 1, wherein said sensor system is arranged to convert the downward deflection into the indication of the weight of the occupying item using a relationship between the downward deflection and weight obtained experimentally.

14. The seat of claim 1, wherein said sensor system comprises at least one spring arranged under said cushion and to expand as a function of the pressure applied to said upper surface of said cushion, and at least one force-measuring device for measuring tension in said at least one spring.

15. The seat of claim 14, wherein said at least one force-measuring device is a strain gage.

16. The seat of claim 15, wherein said sensor system further comprises an interrogator for wirelessly interrogating said strain gage.

17. The seat of claim 1, wherein said cushion comprises a foam layer and a spring system arranged under said foam layer, said sensor system comprising at least one strain gage arranged in association with said spring system to measure strain in said spring system.

18. The seat of claim 1, wherein said sensor system comprises at least one strain gage arranged in a bottom surface or support pan of said cushion to measure strain in said bottom surface or support pan.

19. A method for obtaining an indication of the weight of an occupying item in a vehicular seat, comprising:

arranging a cushion on a support structure of the seat, the cushion having an upper surface over which the occupying item is situated during occupancy of the seat;

arranging a sensor system in a position in which it operatively senses downward deflection of the cushion; and

determining the weight of the occupying item when it applies pressure to the upper surface of the cushion by sensing the downward deflection of the cushion and converting the downward deflection into an indication of the weight of the occupying item.

20. The method of claim 19, wherein the step of determining the weight of the occupying item comprises experimentally deriving a relationship between downward deflection of the cushion and weight of an occupying item applying pressure to the upper surface of the cushion.

21. A method for identifying an occupant of a vehicular seat, comprising:

obtaining an indication of the weight of the occupant in accordance with claim 19, and

classifying the occupant based at least in part on the obtained indication of the weight of the occupant.

22. The method of claim 21, further comprising:

determining an additional morphological characteristic of the occupant; and

classifying the occupant based at least in part on the determined additional morphological characteristic and the obtained indication of the weight of the occupant.

23. A control system for controlling a vehicle component based on occupancy of a seat having a seat support structure and a cushion arranged on the seat support structure, the cushion having an upper surface over which an occupying item is situated during occupancy of the seat and being arranged to be displaced downward during occupant of the seat, the control system comprising:

a sensor system arranged to sense the downward deflection of the cushion and convert the downward deflection into an indication of the weight of the occupying item;

an adjustment system arranged to adjust the component in the vehicle; and

a processor coupled to said sensor system and to said adjustment system for determining an adjustment for the component by said adjustment system based at least in part on the indication of the weight of the occupying item provided by said sensor system.

24. The control system of claim 23, wherein said adjustment system is a system for adjusting deployment of an occupant restraint device.

25. The control system of claim 24, wherein the occupant restraint device is an airbag and said deployment adjustment system is arranged to control at least one of flow of gas into an airbag, flow of gas out of an airbag, rate of generation of gas and amount of generated gas.