Crash pulse energy algorithm for an inflatable restraint system
View Patent ↗An air bag system ( 12 ) includes a controller ( 14 ), a remote satellite sensor ( 16 ), and a deployable air bag ( 18 ). Controller logic for deployment discrimination of an impact event sensitizes an airbag deployment command in response to signals from the satellite sensor. The logic determines a crash-pulse energy term (CPE) which discriminates impact signals which are particularly useful for identifying side impact events.
1. A method of sensitizing an air bag deployment threshold comprising the steps of:
(1) measuring a first acceleration;
(2) measuring a second acceleration in a direction generally opposite the first acceleration;
(3) measuring a third acceleration;
(4) determining if the first acceleration exceeds a predetermined acceleration;
(5) comparing the third acceleration to a reference value, the reference value having a magnitude origin biased in the direction of, and defined in part as a percentage of the second acceleration; and
(6) increasing a crash-pulse energy term in response to the third acceleration increasing above the predetermined acceleration relative to the magnitude origin of said step (5).
2. A method as recited in claim 1 , further comprising the step of:
initiating a predetermined time period in response to said step (4) when a peak of the first acceleration is determined.
3. A method as recited in claim 1 , further comprising the step of:
setting the magnitude origin of the reference value to the greater of: 100 percent of the first acceleration; or a percentage of the first acceleration if the first acceleration is in an anti-crash direction.
4. A method as recited in claim 1 , further comprising the step of:
(7) initiating an increase in the crash-pulse energy term in response to the third acceleration increasing above the second acceleration.
5. A method as recited in claim 1 , further comprising the step of:
(7) terminating the increase in the crash-pulse energy term in response to detecting a peak of the third acceleration.
6. A method as recited in claim 1 , further comprising the step of:
identifying the crash-pulse energy term reaching a predetermined value; and
deploying an air bag in response to the crash-pulse energy term reaching the predetermined value.
7. A method as recited in claim 1 , further comprising the step of:
increasing a sensitivity of an airbag deploy command in response to an increase in the crash-pulse energy term.
8. A method as recited in claim 1 , further comprising the step of:
increasing the likelihood of an airbag deploy command in response to an increase in the crash-pulse energy term.
9. A method as recited in claim 1 , wherein the first, second and third acceleration are in a lateral vehicle direction.
10. A method as recited in claim 1 , further comprising the step of:
setting the magnitude origin of the reference value to 100 percent of the first acceleration.
11. A method of sensitizing an air bag deployment threshold comprising the steps of:
(1) measuring a first acceleration;
(2) determining whether the first acceleration exceeds a predetermined acceleration;
(3) measuring a second acceleration, the second acceleration in a direction generally opposite the first acceleration;
(4) measuring a third acceleration, the third acceleration in a direction generally the same as the first acceleration;
(5) comparing the third acceleration to a reference value, the reference value having a magnitude origin biased in the direction of, and defined in part as a percentage of the second acceleration; and
(6) increasing a crash-pulse energy term in response to the third acceleration increasing above the predetermined acceleration relative to the magnitude origin of said step (5).
12. A method as recited in claim 11 , further comprising the step of:
increasing the crash-pulse energy term only in response to said step (6) occurring within a predetermined time period.
13. A method as recited in claim 11 , further comprising the step of:
increasing the likelihood of a side airbag deploy command in response to an increase in the crash-pulse energy term.
14. A method as recited in claim 11 , further comprising the step of:
setting the magnitude origin of the reference value to the greater of: 100 percent of the first acceleration; or a percentage of the first acceleration if the first acceleration is in an anti-crash direction.
15. A method as recited in claim 11 , further comprising the step of:
terminating the increase in the crash-pulse energy term in response to identifying a peak in the third acceleration.
16. A method as recited in claim 15 , further comprising the step of:
initiating a time period in response to identifying a peak in the third first acceleration.
17. A method as recited in claim 11 , further comprising the step of:
increasing the likelihood of an airbag deploy command in response to an increase in the crash-pulse energy term.