Method and apparatus for sensing a vehicle crash condition using velocity enhanced acceleration crash metrics

• US 5,587,906 A
• Filed: 06/13/1994
• Issued: 12/24/1996
• Est. Priority Date: 06/13/1994
• Status: Expired due to Term

• Current Assignee: TRW Limited (Zeppelin - Stiftung der Stadt Friedrichshafen)
• Original Assignee: TRW Limited (Zeppelin - Stiftung der Stadt Friedrichshafen)
• Inventors: Carlin, Mark A., Bormann, James E., Muckley, Ronald A., McCurdy, Roger A., McIver, George W.
• Primary Examiner(s): Teska, Kevin J.
• Assistant Examiner(s): Walker, Tyrone V.
• Application Number:
  US08/258,952
• Time in Patent Office: 925 Days
• Field of Search: 364/424.05, 340/436, 340/669, 280/734, 280/735, 180/274, 180/282, 307/10.1
• US Class Current: 701/36
• CPC Class Codes: B60R 21/0132 responsive to vehicle motion parameters , e.g. to vehicle longitudinal or transversal deceleration or speed value

Abstract

An apparatus for sensing a vehicle crash condition includes an accelerometer (20) for sensing a vehicle crash condition and for providing a signal having a characteristic indicative of the vehicle crash condition. A crash velocity determining circuit (74) determines a crash velocity value (78) from the accelerometer. Crash metric determining circuits (80, 82, 94, 96, 104, 108) determine crash metric values functionally related to acceleration. Threshold determining circuits (88, 98, 112) determining associated threshold values functionally related to the determined crash velocity value (78). Comparators (90, 100, 116) compare the determined crash metric values against associated threshold values. A controller (34) provides a control signal to control actuation of a restraining device in response to the comparison. A shape monitoring circuit (120) determines if the shape of the acceleration signal matches a predetermined shape. If the shape matches, the controller provides the control signal.

Claims

1. An apparatus for sensing a vehicle crash condition comprising:

acceleration sensing means for sensing a vehicle crash condition and for providing a crash acceleration signal having a characteristic indicative of the vehicle crash condition;

crash velocity determining means connected to said acceleration sensing means for determining a crash velocity value from said crash acceleration signal;

crash metric determining means connected to said acceleration sensing means for determining a crash metric value functionally related to said acceleration signal;

threshold determining means for determining a velocity based threshold value functionally related to said determined crash velocity value, said velocity based threshold value varying as a function of said determined crash velocity value;

comparing means for comparing said determined crash metric value against said velocity based threshold value and for providing a signal indicative of the comparison; and

control signal means for providing a control signal in response to said comparing means when said determined crash metric exceeds said velocity based threshold value.

2. The apparatus of claim 1 wherein said crash metric determining means includes means for determining a band-limited value functionally related to the value of the crash acceleration signal.

3. The apparatus of claim 1 wherein said crash metric determining means includes means for determining a value functionally related to crash violence.

4. The apparatus of claim 3 wherein said crash metric determining means includes means for determining a value functionally related to the square of the crash acceleration signal.

5. The apparatus of claim 3 wherein said crash metric determining means includes means for determining a value functionally related to the sum of the squares of the crash acceleration signal.

6. An apparatus for sensing a vehicle crash condition comprising:

acceleration sensing means for sensing a vehicle crash condition and for providing a crash acceleration signal having a characteristic indicative of the vehicle crash condition;

crash velocity determining means connected to said acceleration sensing means for determining crash velocity value from said a crash acceleration signal;

a plurality of crash metric determining means connected to said acceleration sensing means, each crash metric determining means determining a crash metric value functionally related to said crash acceleration signal;

a plurality of velocity based threshold determining means, each crash metric having an associated velocity based threshold determining means, each threshold determining means determining its associated velocity based threshold value functionally related to said determined crash velocity value so that each of said velocity based threshold values varies as a function of said determined crash velocity value;

comparing means for comparing each of said determined crash metric value against its associated velocity based threshold value and for providing a signal indicative of the comparison; and

control signal means for providing a control signal in response to any of said determined crash metrics exceeding its associated velocity based threshold value.

7. The apparatus of claim 6 wherein said crash metric determining means includes means for determining a band-limited value functionally related to the value of the crash acceleration signal.

8. The apparatus of claim 6 wherein said crash metric determining means includes means for determining a value functionally related to crash violence.

9. The apparatus of claim 8 wherein said crash metric determining means includes means for determining a value functionally related to the square of the crash acceleration signal.

10. The apparatus of claim 8 wherein said crash metric determining means includes means for determining a value functionally related to the sum of the squares of the crash acceleration signal.

11. An apparatus for sensing a vehicle crash condition comprising:

acceleration sensing means for sensing a vehicle crash condition and for providing an acceleration signal having a characteristic indicative of the vehicle crash condition;

crash velocity determining means connected to said acceleration sensing means for determining a crash velocity value from said acceleration signal;

first crash metric determining means connected to said acceleration sensing means for determining a value proportional to said acceleration signal;

first crash metric threshold determining means associated with said first crash metric determining means for determining a first velocity based threshold value functionally related to said determined crash velocity value;

second crash metric determining means connected to said acceleration sensing means for determining a value proportional to said acceleration signal squared;

second crash metric threshold determining means associated with said second crash metric determining means for determining a second velocity based threshold value functionally related to said determined crash velocity value;

third crash metric determining means connected to said acceleration sensing means for determining a value proportional to a sum of said acceleration signal squared;

third crash metric threshold determining means associated with said third crash metric determining means for determining a third velocity based threshold value functionally related to said determined crash velocity value;

fourth crash metric determining means connected to said acceleration sensing means for determining a value proportional to a shape of said acceleration signal;

shape comparing means for comparing said crash metric shape against a predetermined shape;

comparing means for comparing each of said determined crash metric values against its associated velocity based threshold value and for providing a signal indicative of the comparison; and

control signal means for providing a control signal in response to any of said determined crash metrics exceeding its associated velocity based threshold value as indicated by said comparing means or said compared shape is equal to said predetermined shape.

12. An apparatus for sensing a vehicle crash condition comprising:

acceleration sensing means for sensing a vehicle crash condition and for providing a crash acceleration signal having a characteristic indicative of the vehicle crash condition;

crash velocity determining means connected to said acceleration sensing means for determining crash velocity value from said crash acceleration signal;

crash metric determining means connected to said acceleration sensing means for determining a crash metric value functionally related to said crash acceleration signal, said value being indicative of a type of crash event; and

control signal means for providing a control signal in response to (i) said determined crash velocity value being greater than a predetermined value and (ii) said crash metric value indicating that a deployment crash event is occurring.

13. A method for sensing a vehicle crash condition, said method comprising the steps of:

sensing a vehicle crash condition and providing a crash acceleration signal having a characteristic indicative of the vehicle crash deceleration;

determining a crash velocity value from said crash acceleration signal;

determining a plurality of crash metric values functionally related to said crash acceleration signal;

determining an associated velocity based threshold value for each crash metric, each determined velocity based threshold value being functionally related to said determined crash velocity value so that each of said determined velocity based threshold values varies as a function of said determined crash velocity value;

comparing each of said determined crash metric values against its associated velocity based threshold value and providing a signal indicative of the comparison; and

providing a control signal in response to any of said determined crash metrics exceeding its associated velocity based threshold value.

14. The method of claim 13 wherein said step of determining a crash metric value includes determining a band-limit value functionally related to the value of the crash acceleration signal.

15. The method of claim 13 wherein said step of determining a crash metric includes determining a value functionally related to crash violence.

16. The method of claim 15 wherein said step of determining a crash metric includes determining a value functionally related to the square of the crash acceleration signal.

17. The apparatus of claim 15 wherein said step of determining a crash metric includes determining a value functionally related to the sum of the squares of the crash acceleration signal.

18. An apparatus for sensing a vehicle crash condition comprising:

acceleration sensing means for sensing a vehicle crash condition and for providing a crash acceleration signal having a characteristic indicative of the vehicle crash condition;

crash velocity determining means connected to said acceleration sensing means for determining a crash velocity value from said crash acceleration signal;

a plurality of crash metric determining means connected to said acceleration sensing mean, each crash metric determining means determining a crash metric value functionally related to said crash acceleration signal;

means for determining the shape of the crash acceleration signal as a function of time;

a plurality of velocity based threshold determining means, each crash metric having an associated velocity based threshold determining means, each threshold determining means determining its associated velocity based threshold value functionally related to said determined crash velocity value;

comparing means for comparing each of said determined crash metric value against its associated velocity based threshold value and for providing a signal indicative of the comparison; and

control signal means for providing a control signal in response to any of said determined crash metrics exceeding its associated velocity based threshold value and for providing said control signal if said determined shape of said crash acceleration signal is equal to a predetermined shape.

19. A method for sensing a vehicle crash condition, said method comprising the steps of:

sensing a vehicle crash condition and providing a crash acceleration signal having a characteristic indicative of the vehicle crash deceleration;

determining a crash velocity value from said crash acceleration signal;

determining a plurality of crash metric values functionally related to said crash acceleration signal;

determining an associated velocity based threshold value for each crash metric, each determined velocity based threshold value being functionally related to said determined crash velocity value;

determining the shape of the crash acceleration signal as a function of time;

comparing each of said determined crash metric values against its associated velocity based threshold value and providing a signal indicative of the comparison; and

providing a control signal in response to any of said determined crash metrics exceeding its associated velocity based threshold value and providing said control signal if said determined shape of said crash acceleration signal is equal to a predetermined shape.