Predictor/check crash discriminator

• US 5,508,918 A
• Filed: 10/08/1991
• Issued: 04/16/1996
• Est. Priority Date: 06/04/1991
• Status: Expired due to Fees

• Current Assignee: Automotive Systems Laboratory, Incorporated (Ningbo Junsheng Investment Group Co., Ltd.)
• Original Assignee: Automotive Systems Laboratory, Incorporated (Ningbo Junsheng Investment Group Co., Ltd.)
• Inventors: Gioutsos, Tony
• Primary Examiner(s): Trans, Vincent N.
• Application Number:
  US07/773,017
• Time in Patent Office: 1,652 Days
• Field of Search: 364/424.05, 280/735, 180/274, 180/282, 340/436
• US Class Current: 701/46
• CPC Class Codes: B60R 21/013 including means for detecting collisions, impending collisions or roll-over
• CPC Class Codes: B60R 21/0133 by integrating the amplitude of the input signal
• CPC Class Codes: B60R 21/01336 using filtering

Abstract

A system and method for triggering deployment of a vehicle air bag in response to a crash or sudden vehicle deceleration wherein a modified acceleration value is obtained by subtracting a correction term from data representative of sensed instantaneous vehicle acceleration; integrating the modified acceleration value to obtain a modified velocity value; estimating the transitory jerk of the acceleration data using a rank filter; obtaining the product of the estimated transitory jerk and the modified velocity; comparing the resulting velocity-jerk product to a threshold value therefor; and triggering deployment of the air bag when the velocity-jerk product exceeds the threshold value therefor.

Claims

1. A method for triggering deployment or actuation of a vehicle safety device, said method comprising the steps of:

sampling data representative of instantaneous vehicle acceleration;

storing consecutive values of said acceleration data in a buffer;

correcting said consecutive values of said acceleration data by subtracting a correction value therefrom;

integrating said corrected acceleration data to determine a modified vehicle velocity value;

calculating a transitory jerk value based on said stored values of said acceleration data;

multiplying said modified vehicle velocity value and said transitory jerk value to obtain a modified, transitory velocity-jerk product;

comparing said velocity-jerk product with a first threshold value; and

triggering deployment or actuation of said safety device when said velocity-jerk product exceeds said threshold value.

2. The method of claim 1, further including the steps of:

comparing said transitory jerk value with a second threshold value;

comparing said velocity-jerk product with a third threshold value of lesser magnitude than said first threshold value; and

triggering deployment or actuation of said safety device when said transitory jerk value and said velocity-jerk product exceed said second and third threshold values, respectively.

3. A method for determining if an event requires actuation of a vehicle safety device, said method comprising the steps of:

receiving information representative of instantaneous vehicle acceleration;

determining a first measure which is evaluative of said received instantaneous vehicle acceleration information in relation to time;

determining a second measure correlated with the progress of said event based on said received acceleration information;

determining an estimated vehicle acceleration value based on said first measure and said second measure, wherein said second measure is used as a time value;

comparing said first measure with a first predetermined threshold value;

comparing said estimated acceleration value with a second predetermined threshold value;

comparing said estimated acceleration value with a second predetermined threshold value; and

actuating said vehicle safety device if said first measure has exceeded said first predetermined threshold value and said estimated acceleration value has exceeded said second predetermined threshold value.

4. The method of claim 3 further comprising:

comparing said estimated vehicle acceleration value with a third predetermined threshold value, wherein said third predetermined threshold value is greater than said second predetermined threshold value; and

actuating said vehicle safety device if said estimated acceleration value exceeds said third predetermined threshold value.

5. The method of claim 3 wherein said step of determining said first measure includes the step of determining a jerk value from the slope of said received acceleration information in relation to time.

6. The method of claim 5 further comprising the step of determining said second measure by integrating said received acceleration information to generate a vehicle velocity value, and wherein said estimated acceleration value is determined by multiplying said jerk value with said vehicle velocity value.

7. The method of claim 3 wherein said step of receiving comprises the steps of:

sampling said acceleration information; and

storing said sampled information in a memory means as digital data.

8. The method of claim 7 further comprising the step of rank-order filtering said stored digital data, wherein said step of determining said first measure comprises generating a median rank-order value from said rank-order filtering.

9. The method of claim 3 wherein said first and said second predetermined threshold values are sequentially exceeded.

10. The method of claim 3 including the step of modifying said received acceleration information with a modification value, and wherein said received acceleration information is used in determining said first measure and said modified acceleration information is used in determining said second measure.

11. A system for determining if an event requires actuation of a vehicle safety device comprising:

sampling means for sampling raw information representative of instantaneous vehicle acceleration;

first determining means responsive to said received acceleration information for determining a first measure evaluative of said received acceleration information in relation to time;

second determining means responsive to said received acceleration information for determining a second measure correlated with the progress of said event;

second determining means responsive to said received acceleration information for determining a second measure correlated with the progress of said event;

third determining means responsive to said first measure and said second measure for determining an estimated vehicle acceleration value, wherein said second measure is used as a time value;

first comparing means responsive to said first measure for generating a first output signal if said first measure has exceeded a first predetermined threshold value;

second comparing means responsive to said estimated vehicle acceleration value for generating a second output signal if said estimated acceleration value has exceeded a second predetermined threshold value; and

means for actuating said vehicle safety device in response to the generation of said first and said second output signals.

12. The system of claim 11 wherein said second comparing means generates a third output signal when said estimated acceleration value exceeds a third predetermined threshold value, said third predetermined threshold value being greater than said second predetermined threshold value;

and wherein said actuating means actuates said vehicle safety device in response to the generation of said third output signal.

13. The system of claim 11 wherein said receiving means comprises:

a sampling means for generating N samples of said acceleration information; and

a FIFO storage means for storing said N samples of information.

14. The system of claim 13 wherein said first determining means comprises:

a first rank-order filter for rank-order filtering a newest first set of samples stored in said storage means;

a second rank-order filter for rank-order filtering an oldest second set of samples stored in said storage means; and

a first subtracting means connected to said first and said second rank-order filter for subtracting said second set of samples from said first set of samples to generate said first measure.

15. The system of claim 14 wherein said third determining means for determining said estimated acceleration value comprises:

a second subtracting means connected to said second rank-order filter for subtracting a scale factor from said second set of samples;

an accumulator means for accumulating the output of said second subtracting means; and

a multiplying means connected to said accumulator means and said first subtracting means for generating said estimated vehicle acceleration value.

16. A method of predicting vehicle acceleration information for determining if an event requires actuation of a vehicle safety device, said method comprising the steps of:

sampling raw information representative of instantaneous vehicle acceleration;

damping said sampled acceleration information with a predetermined scale factor;

determining a first measure evaluative of said sampled acceleration information in relation to time;

determining a second measure correlated with the progress of said event;

determining an estimated acceleration value by multiplying said first measure with said second measure;

comparing said estimated acceleration value of a predetermined threshold value; and

actuating said vehicle safety device if said estimated acceleration exceeds said predetermined threshold value.

17. The method of claim 16 wherein said scale factor is a predetermined constant representative of an acceleration which a passenger can be expected to withstand without requiring actuation of said vehicle safety device.

18. The method of claim 16 wherein said scale factor is based on a function of time representative of an acceleration which a passenger can be expected to withstand without requiring actuation of said vehicle safety device.

19. The method of claim 16 wherein said step of determining said first measure includes the step of determining a jerk value from the slope of said sampled acceleration information in relation to time.