Seat belt occupant sensor

• US 6,581,960 B1
• Filed: 12/14/1999
• Issued: 06/24/2003
• Est. Priority Date: 12/14/1999
• Status: Active Grant

• Current Assignee: Ford Global Technologies, LLC (Ford Motor Company)
• Original Assignee: Ford Global Technologies, LLC (Ford Motor Company)
• Inventors: Hagen, Markus, Brosig, Ralf, Schondorf, Steven Yellin
• Primary Examiner(s): Dickson, Paul N.
• Assistant Examiner(s): To, Toan
• Application Number:
  US09/460,825
• Time in Patent Office: 1,288 Days
• Field of Search: 280/728.1, 280/735, 280/801.1, 280/803, 280/807, 180/271, 180/273
• US Class Current: 280/735
• CPC Class Codes: B60R 21/01532 using electric or capacitive field sensors
• CPC Class Codes: B60R 21/01544 detecting seat belt parameters, e.g. length, tension or height-adjustment
• CPC Class Codes: B60R 21/01546 using belt buckle sensors
• CPC Class Codes: B60R 22/12 Construction of belts or harnesses B60R21/18 takes precedence ; woven fabrics for safety belts D03D1/0005

Abstract

An occupant sensor system 12 is coupled to an airbag deployment system 14. Occupant sensor system 12 has an occupant sensor 24 that comprises a seat belt and a plurality of wires extending a predetermined length within seat belt 26. Wires 28 are coupled to a controller 22 that is used to sense a changing electrical characteristic of wires 28 such as capacitance or inductance to determine the presence of an occupant. Controller 22 in response to the signal from occupant sensor 24 may then adjust the deployment of an airbag 18.

Claims

1. An occupant sensor comprising:

a seat belt;

a plurality of wires extending a predetermined length of said seat belt and conforming to a shape of said seat belt; and

a controller coupled to said plurality of wires measuring a change in an electrical characteristic of the wire and indicating the presence of an occupant in response to said electrical characteristic corresponding to a change in a shape of said wires.

2. An occupant sensor as recited in claim 1 wherein said electrical characteristics comprises inductance.

3. An occupant sensor as recited in claim 1 wherein said electrical characteristics comprises capacitance.

4. An airbag system comprising an occupant sensor as recited in claim 1 wherein said controller comprises an airbag controller.

5. An occupant sensor as recited in claim 1 wherein said wires extend within said seat belt.

6. An airbag deployment system for an automotive vehicle comprising:

an airbag;

a seat belt;

an occupant sensor having wires extending a predetermined length of said seat belt and conforming to a shape of said seat belt; and

an airbag controller module coupled to said sensor, said controller measuring a change in an electrical characteristic of the wire and indicating the presence of an occupant in response to said electrical characteristic corresponding to a change in a shape of said wires.

7. An airbag deployment system as recited in claim 6 further comprising a memory coupled to said airbag controller.

8. An airbag deployment system as recited in claim 6 wherein said airbag controller comprises a constant current source coupled to said occupant sensor.

9. An airbag deployment system as recited in claim 6 wherein said airbag controller comprises a constant voltage source coupled to said occupant sensor.

10. An airbag deployment system as recited in claim 6 wherein said airbag controller comprises a current to voltage converter coupled to said occupant sensor.

11. An airbag deployment system as recited in claim 6 further comprising a buckle sensor coupled to the airbag controller indicating a buckled seatbelt.

12. An airbag deployment system as recited in claim 6 wherein said electrical characteristics comprises inductance.

13. An airbag deployment system as recited in claim 6 wherein said electrical characteristics comprises capacitance.

14. An airbag deployment system as recited in claim 6 wherein said wires extend within said seat belt.

15. A method of determining the presence of an occupant within an automotive vehicle comprising the steps of:

passing an electrical signal through wires within a length of a seat belt, said wires have a shape;

measuring a seat belt electrical characteristic of said wires corresponding to the shape of said wires;

comparing the seat belt electrical characteristic to a known characteristic; and

indicating the presence of an occupant in response to the step of comparing.

16. A method of operating an airbag system comprising the steps of determining the presence of an occupant as recited in claim 15 and adjusting an airbag deployment strategy in response to step of comparing.

17. A method as recited in claim 15 further comprising the step of determining the seat belt buckle status.

18. A method as recited in claim 15 wherein the step of applying an electrical signal comprises applying a square wave through wires.

19. A method as recited in claim 15 wherein the step of measuring an electrical characteristic comprises measuring a capacitance of said wires.

20. A method as recited in claim 15 wherein the step of measuring an electrical characteristic comprises measuring a inductance of said wires.

21. An occupant sensor comprising:

a seat belt;

a plurality of wires extending a predetermined length of said seat belt and conforming to a shape of said seat belt; and

a controller coupled to said plurality of wires measuring a change in an electrical characteristic of the wire and indicating the presence and size of an occupant in response to said electrical characteristic corresponding to a change in a shape of said wires.

22. An airbag deployment system for an automotive vehicle comprising:

an airbag;

a seat belt;

an occupant sensor having wires extending a predetermined length of said seat belt and conforming to a shape of said seat belt; and

an airbag controller module coupled to said sensor, said controller measuring a change in an electrical characteristic of the wire and indicating the presence and size of an occupant in response to said electrical characteristic corresponding to a change in a shape of said wires.

23. A method of determining the presence of an occupant within an automotive vehicle comprising the steps of:

passing an electrical signal through wires within a length of a seat belt, said wires have a shape;

measuring a seat belt electrical characteristic of said wires corresponding to the shape of said wires;

comparing the seat belt electrical characteristic to a known characteristic; and

indicating the presence and size of an occupant in response to the step of comparing.