METHOD OF OPTIMIZING THRESHOLD FOR AN AIRBAG SUPPRESSION SYSTEM IN A VEHICLE

• US 20130073148A1
• Filed: 09/21/2011
• Published: 03/21/2013
• Est. Priority Date: 09/21/2011
• Status: Active Grant

• Current Assignee: GM Global Technology Operations LLC (General Motors Company)
• Original Assignee: GM Global Technology Operations LLC (General Motors Company)
• Inventors: Dolan, John R., Corrion, Steven G., Gleason, Joseph P.
• Granted Patent: US 8,862,332 B2
• Time in Patent Office: Days
• US Class Current: 701/45
• CPC Class Codes: B60R 21/013 including means for detecting collisions, impending collisions or roll-over
• CPC Class Codes: B60R 22/105 for children adaptation of children's seats for seat belts B60N2/265, B60N2/2803
• CPC Class Codes: B60R 22/36 self-locking in an emergency B60R22/3405 , B60R22/343 take precedence
• CPC Class Codes: B60R 22/415 with additional means allowing a permanent locking of the retractor during the wearing of the belt

Abstract

A method is presented of optimizing an airbag suppression threshold for an airbag suppression system in a vehicle. The method includes defining a first value as the airbag suppression threshold such that deployment of an airbag is suppressed above the first value. Next, one or more factors indicative of a presence of a child restraint seat in the vehicle seat are determined. The airbag suppression threshold is set to a predefined second value when each of the factors are met. The factors include determining whether a locking feature in a set belt webbing retractor is in a first state configured to prevent withdrawal of the seat belt webbing. Other factors may include determining whether a speed of the vehicle is within a predetermined speed range and whether a load applied to the vehicle seat is within a predetermined seatload range.

Claims

1. A method of optimizing an airbag suppression threshold for an airbag suppression system in a vehicle having a vehicle seat and an airbag, the method comprising:

defining a first value as the airbag suppression threshold such that deployment of the airbag is suppressed above the first value;

determining one or more factors indicative of a presence of a child restraint seat in the vehicle seat; and

selectively setting the airbag suppression threshold to a predefined second value when each of the factors are met.

2. The method of claim 1, wherein:

the vehicle includes a retractor having a spool such that a seat belt webbing is wound around the spool; and

the factors include;

determining whether a locking feature in the retractor is in a first state configured to block rotation of the spool in a belt-withdrawal direction.

3. The method of claim 1, wherein the factors include:

determining whether a load applied to the vehicle seat remains above a predetermined adult load for at least a predetermined minimum time.

4. The method of claim 3, wherein the predetermined adult load is 100 pounds and the predetermined minimum time is 30 seconds.

5. The method of claim 1, wherein the factors include:

determining whether a speed of the vehicle is within a predetermined speed range.

6. The method of claim 5, wherein the predetermined speed range is 0-10 kilometres per hour.

7. The method of claim 1, wherein the factors include:

determining whether a load applied to the vehicle seat is within a predetermined seat-load range.

8. The method of claim 7, wherein the seat-load range is approximately between 20 and 38 pounds.

9. The method of claim 1, wherein the vehicle includes a seat belt webbing, a retractor and the factors include:

determining whether a locking feature in the retractor remains in a first state configured to prevent withdrawal of the seat belt webbing for at least a predefined minimum locking time.

10. The method of claim 9, wherein the predefined minimum locking time is 10 seconds.

11. The method of claim 1, wherein the airbag suppression system is pressure-based such that deployment of the airbag is suppressed when a pressure on the vehicle seat is above the first value.

12. A method of optimizing an airbag suppression threshold for an airbag suppression system in a vehicle having a vehicle seat, an airbag, a seat belt webbing and a retractor, the method comprising:

defining a first value as the airbag suppression threshold such that the airbag is suppressed above the first value;

determining one or more factors indicative of a presence of a child restraint seat in the vehicle seat;

selectively setting the airbag suppression threshold to a predefined second value when each of the factors are met;

wherein the factors include;

determining whether a locking feature in the retractor is in a first state configured to prevent withdrawal of the seat belt webbing;

determining whether an adult classification has been made with high confidence;

determining whether a speed of the vehicle is within a predetermined speed range;

determining whether a load applied to the vehicle seat is within a predetermined seatload range; and

determining whether the locking feature in the seat belt webbing retractor remains in the first state configured to prevent withdrawal of the seat belt webbing for at least a predefined minimum locking time.

13. The method of claim 12, wherein the locking feature is configured to enter the first state when the seat belt webbing is fully extended.

14. The method of claim 12, wherein said determining whether an adult classification has been made with high confidence includes determining whether the load applied to the vehicle seat remains above a predetermined adult load for at least a predetermined minimum time.

15. A retractor for seat belt webbing, the retractor comprising:

a spool configured for winding the seat belt webbing, the spool being rotatable about a first axis in a belt-winding direction and in an opposite belt-withdrawal direction;

a ratchet rotatable about the first axis;

a locking feature defined by a lever movable between first and second positions, wherein the lever in the first position blocks rotation of the ratchet in the belt-withdrawal direction, thereby blocking rotation of the spool in the belt-withdrawal direction;

a control mechanism for controlling movement of the lever; and

a locking sensor configured to detect the position of the lever.

16. The retractor of claim 15, further comprising:

a magnetic element fixedly connected to the lever; and

wherein the locking sensor includes one or more hall sensors configured to sense the position of the lever by detecting a location of the magnetic element.

17. The retractor of claim 15, wherein the locking sensor is an optical proximity sensor configured to detect the position of the lever.

18. The retractor of claim 15, wherein the locking sensor is a mechanical switch that switches between two states as the lever moves between the first and second positions.

19. The retractor of claim 15, further comprising a pawl operatively connected to the lever and configured to engage with the ratchet when the lever is in the first position.

20. The retractor of claim 15, wherein the control mechanism includes a plurality of gears rotatable in response to rotation of the spool.