WEIGHT BASED OCCUPANT CLASSIFICATION SYSTEM FOR CONTROLLING ENABLEMENT OF A PROTECTION DEVICE

• US 20030033065A1
• Filed: 08/09/2001
• Published: 02/13/2003
• Est. Priority Date: 08/09/2001
• Status: Active Grant

• Current Assignee: TRW Vehicle Safety Systems Incorporated (Zeppelin - Stiftung der Stadt Friedrichshafen)
• Original Assignee: TRW Vehicle Safety Systems Incorporated (Zeppelin - Stiftung der Stadt Friedrichshafen)
• Inventors: Vos, Thomas H., Resh, Robert E.
• Granted Patent: US 6,640,175 B2
• Time in Patent Office: Days
• US Class Current: 701/45
• CPC Class Codes: B60R 21/01516 using force or pressure sensing means

Abstract

A method and associated apparatus for controlling actuation of a protection device for an occupant of a vehicle seat (12) having a weight sensor (14) comprises the steps of: determining (44) when the value of an output signal of the weight sensor rises from an initial value; waiting (46) a predetermined period of time (T₂) after the value of the output signal rises from the initial value; determining (48) the weight on the vehicle seat after the predetermined period of time (T₂); comparing (50) the weight on the vehicle seat after the predetermined period of time with a first threshold weight (W₁); enabling (52) actuation of the protection device if the weight on the vehicle seat after the predetermined period of time exceeds the first threshold weight; and disabling (54) actuation of the protection device if the weight on the vehicle seat after the predetermined period of time does not exceed the first threshold weight.

Claims

1. A method of controlling the enabling and disabling of actuation of a protection device for an occupant of a vehicle seat having a weight sensor, said method comprising the steps of:

continually sensing the weight on the vehicle seat and providing an output signal indicative of the sensed weight, the output signal having an initial value;

determining when the value of the output signal of the weight sensor rises from the initial value;

waiting a predetermined period of time after the value of the output signal rises from the initial value;

determining the weight on the vehicle seat after the predetermined period of time; and

,

comparing the weight on the vehicle seat after the predetermined period of time with a first threshold weight and, as a result, either (a) enabling actuation of the protection device if the weight on the vehicle seat after the predetermined period of time exceeds the first threshold weight, or (b) disabling actuation of the protection device if the weight on the vehicle seat after the predetermined period of time does not exceed the first threshold weight.

2. A method as set forth in claim 1 wherein the first threshold weight is a weight indicative of the presence of an adult on the vehicle seat.

3. A method as set forth in claim 1 further comprising the steps of:

determining the weight on the vehicle seat when the protection device is actuated, and

comparing the weight on the vehicle seat with a second threshold weight less than the first threshold weight and, as a result, either (a) maintaining actuation of the protection device if the weight on the vehicle seat exceeds the second threshold weight, or (b) disabling actuation of the protection device if the weight on the vehicle seat does not exceed the second threshold weight.

4. A method as set forth in claim 3 wherein the first threshold weight is a weight indicative of the presence of an adult on the vehicle seat.

5. A method as set forth in claim 4 wherein the second threshold weight is a weight indicative of a vacant vehicle seat.

6. A method as set forth in claim 1 for use in a vehicle having an ignition and further comprising the steps of providing a controller with a memory, and maintaining in the memory, when the vehicle ignition is turned off, a value indicative of the state of actuation of the inflator.

7. A method as set forth in claim 6 further comprising the steps of:

determining the weight on the vehicle seat when the vehicle ignition is turned off; and

thereafter, upon actuation of a door switch of the vehicle or upon the vehicle ignition being turned on,

comparing the weight on the vehicle seat with a second threshold weight less than the first threshold weight and, as a result, either (a) disabling actuation of the protection device if the weight on the vehicle seat does not exceed the second threshold weight, or (b) enabling or maintaining actuation of the protection device if the weight continues to exceed the first threshold weight.

8. A method as set forth in claim 1 for use in a vehicle having an ignition and a door switch and further comprising the steps of:

providing a controller with a memory and maintaining in the memory, when the vehicle ignition is turned off, a value indicative of the state of actuation of the inflator;

determining the weight on the vehicle seat in response to actuation of the door switch when the vehicle ignition is turned off; and

thereafter

comparing the weight on the vehicle seat with a second threshold weight less than the first threshold weight and, as a result, disabling actuation of the protection device if the weight on the vehicle seat does not exceed the second threshold weight.

9. A method as set forth in claim 1 further comprising the steps of:

determining the rate of increase of the weight on the vehicle seat and providing an output signal indicative of the rate of increase;

comparing the rate of increase of the weight on the vehicle seat with a first threshold rate;

enabling actuation of the protection device if the rate of increase of the weight on the vehicle seat exceeds the first threshold rate; and

disabling actuation of the protection device if the rate of increase of the weight on the vehicle seat does not exceed the first threshold rate.

10. A method as set forth in claim 9 wherein the first threshold rate is a rate of weight increase indicative of an adult sitting on the vehicle seat.

11. A method of controlling enabling and disabling of actuation of a protection device for an occupant of a vehicle seat having a weight sensor, said method comprising the steps of:

continually sensing the weight on the vehicle seat and providing an output signal indicative of the sensed weight;

determining the rate of increase of the weight on the vehicle seat and providing an output signal indicative of the rate of increase;

comparing the rate of increase of the weight on the vehicle seat with a first threshold rate;

enabling actuation of the protection device if the rate of increase of the weight on the vehicle seat exceeds the first threshold rate; and

disabling actuation of the protection device if the rate of increase of the weight on the vehicle seat does not exceed the first threshold rate.

12. A method as set forth in claim 11 wherein the first threshold rate is a rate of weight increase indicative of an adult sitting on the vehicle seat.

13. An apparatus for controlling enabling and disabling of actuation of a protection device for an occupant of a vehicle seat having a weight sensor, said apparatus comprising:

a sensor for sensing the weight on the vehicle seat and for providing an output signal indicative of the sensed weight, the output signal having an initial value;

means for determining when the value of the output signal of the weight sensor rises from the initial value;

means for determining the weight on the vehicle seat at a predetermined period of time after the value of the output signal rises from the initial value; and

means for comparing the weight on the vehicle seat after the predetermined period of time with a first threshold weight and, as a result, either (a) enabling actuation of the protection device if the weight on the vehicle seat after the predetermined period of time exceeds the first threshold weight, or (b) disabling actuation of the protection device if the weight on the vehicle seat after the predetermined period of time does not exceed the first threshold weight.

14. An apparatus as set forth in claim 13 wherein the first threshold weight is a weight indicative of the presence of an adult on the vehicle seat.

15. An apparatus as set forth in claim 13 comprising means for comparing the weight on the vehicle seat, when actuation of the protection device is enabled, with a second threshold weight less than the first threshold weight and, as a result, either (a) maintaining actuation of the protection device if the weight on the vehicle seat exceeds the second threshold weight, or (b) disabling actuation of the protection device if the weight on the vehicle seat does not exceed the second threshold weight.

16. A method as set forth in claim 15 wherein the second threshold weight is a weight indicative of a vacant vehicle seat.

17. An apparatus as set forth in claim 13 for use in a vehicle having an ignition switch, said apparatus further comprising:

a controller with a memory for maintaining, when the vehicle ignition is turned off, a value indicative of the state of actuation of the inflator; and

means for determining the weight on the vehicle seat when the vehicle ignition is turned off, and for, thereafter, comparing the weight on the vehicle seat with a second threshold weight less than the first threshold weight and, as a result, disabling actuation of the protection device if the weight on the vehicle seat does not exceed the second threshold weight.

18. An apparatus as set forth in claim 13 for use in a vehicle having an ignition and a door switch, said apparatus further comprising:

a controller with a memory for maintaining, when the vehicle ignition is turned off, a value indicative of the state of actuation of the inflator; and

means for determining the weight on the vehicle seat in response to actuation of the door switch when the vehicle ignition is turned off, and for, thereafter, comparing the weight on the vehicle seat with a second threshold weight less than the first threshold weight and, as a result, disabling actuation of the protection device if the weight on the vehicle seat does not exceed the second threshold weight.

19. An apparatus as set forth in claim 13 further comprising means for comparing the rate of increase of the weight on the vehicle seat with a first threshold rate and for either (a) enabling actuation of the protection device if the rate of increase of the weight on the vehicle seat exceeds the first threshold rate, or (b) disabling actuation of the protection device if the rate of increase of the weight on the vehicle seat does not exceed the first threshold rate.

20. An apparatus as set forth in claim 19 wherein the first threshold rate is a rate of weight increase indicative of an adult sitting on said vehicle seat.

21. An apparatus for controlling enabling and disabling of actuation of a protection device for an occupant of a vehicle seat having a weight sensor, said apparatus comprising:

means for continually sensing the weight on the vehicle seat and providing an output signal indicative of the sensed weight;

means for determining the rate of increase of the weight on the vehicle seat and providing an output signal indicative of the rate of increase; and

means for comparing the rate of increase of the weight on the vehicle seat with a first threshold rate and for either (a) enabling actuation of the protection device if the rate of increase of the weight on the vehicle seat exceeds the first threshold rate, or (b) disabling actuation of the protection device if the rate of increase of the weight on the vehicle seat does not exceed the first threshold rate.

22. An apparatus as set forth in claim 21 wherein the first threshold rate is a rate of weight increase indicative of an adult sitting on the vehicle seat.