Airbag deployment device and control
First Claim
1. In a vehicle having an impact sensor, a seatbelt restraint sensor, an airbag module and a control module having a memory and a timer, said impact sensor operable for generating an impact signal in response to a collision involving said vehicle, said seatbelt restraint sensor operable for generating a restraint signal indicating that a vehicle occupant is restrained by a seatbelt restraint, said airbag module including an inflator having first and second charges, first and second squib circuits and an airbag, said first squib circuit including a first squib coupled to said first charge and operable for igniting said first charge, said second squib circuit including a second squib coupled to said second charge and operable for igniting said second charge, said control module coupled to said impact sensor, said seatbelt restraint sensor and said first and second squib circuits, said control module receiving said impact signal and said restraint signal, said control module operable for selectively generating first and second squib pulses to cause said first and second squibs, respectively, to ignite said first and second charges, respectively, a method for controlling deployment of said airbag comprising the steps of:
- determining whether a collision having an impact magnitude exceeding a predetermined initial impact magnitude value has occurred;
setting said timer to zero and starting said timer;
determining whether said impact magnitude continues to exceed said initial impact magnitude;
determining whether said impact magnitude exceeds a predetermined LOW impact magnitude value if said impact magnitude continues to exceed said initial impact magnitude;
determining whether a value in said timer is less than predetermined high timer value if said impact magnitude exceeds said LOW impact magnitude value;
determining whether said impact magnitude exceeds a HIGH impact magnitude value if said timer value does not exceed said high timer value;
generating said first and second squib pulses if said impact magnitude exceeds said HIGH impact magnitude value and said timer value is less than said high timer value, said first and second squib pulses thereby causing said first and second squibs, respectively, to ignite said first and second charges, respectively, and inflating said airbag at a predetermined high inflation rate; and
generating at least one of said first and second squib pulses if said impact magnitude exceeds said LOW impact magnitude value, said at least one of said first and second squib pulses thereby causing at least one of said first and second charges to ignite and inflate said airbag at an inflation rate less than said predetermined high inflation rate.
20 Assignments
0 Petitions
Accused Products
Abstract
A method for controlling an airbag system is provided. The airbag system includes an airbag module which may be deployed at different rates to optimize performance of the airbag module to a given impact. The airbag system includes a control module, an impact sensor, a seatbelt restraint sensor and an airbag module. The airbag module includes an inflator having two independent squibs, a first one of the squibs being coupled to a first charge and a second one of the squibs being coupled to a second charge. The method monitors various vehicle dynamics and controls the generation of first and second squib pulses which cause the deployment of the first and second charges so as to optimize the rate at which the airbag is deployed for an impact of a given magnitude. The method also monitors the integrity of each squib circuit and when a fault in a squib circuit is detected, the deployment algorithm is modified to ensure that the airbag will deploy.
59 Citations
20 Claims
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1. In a vehicle having an impact sensor, a seatbelt restraint sensor, an airbag module and a control module having a memory and a timer, said impact sensor operable for generating an impact signal in response to a collision involving said vehicle, said seatbelt restraint sensor operable for generating a restraint signal indicating that a vehicle occupant is restrained by a seatbelt restraint, said airbag module including an inflator having first and second charges, first and second squib circuits and an airbag, said first squib circuit including a first squib coupled to said first charge and operable for igniting said first charge, said second squib circuit including a second squib coupled to said second charge and operable for igniting said second charge, said control module coupled to said impact sensor, said seatbelt restraint sensor and said first and second squib circuits, said control module receiving said impact signal and said restraint signal, said control module operable for selectively generating first and second squib pulses to cause said first and second squibs, respectively, to ignite said first and second charges, respectively, a method for controlling deployment of said airbag comprising the steps of:
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determining whether a collision having an impact magnitude exceeding a predetermined initial impact magnitude value has occurred;
setting said timer to zero and starting said timer;
determining whether said impact magnitude continues to exceed said initial impact magnitude;
determining whether said impact magnitude exceeds a predetermined LOW impact magnitude value if said impact magnitude continues to exceed said initial impact magnitude;
determining whether a value in said timer is less than predetermined high timer value if said impact magnitude exceeds said LOW impact magnitude value;
determining whether said impact magnitude exceeds a HIGH impact magnitude value if said timer value does not exceed said high timer value;
generating said first and second squib pulses if said impact magnitude exceeds said HIGH impact magnitude value and said timer value is less than said high timer value, said first and second squib pulses thereby causing said first and second squibs, respectively, to ignite said first and second charges, respectively, and inflating said airbag at a predetermined high inflation rate; and
generating at least one of said first and second squib pulses if said impact magnitude exceeds said LOW impact magnitude value, said at least one of said first and second squib pulses thereby causing at least one of said first and second charges to ignite and inflate said airbag at an inflation rate less than said predetermined high inflation rate. - View Dependent Claims (2, 3, 4, 5, 6, 7, 8, 9, 10, 11)
determining whether said vehicle occupant is restrained by said seatbelt restraint;
selecting a first set of inflation parameters if said vehicle occupant is restrained by said seatbelt restraint, said first set of inflation parameters having a plurality of first predetermined impact magnitude thresholds;
storing said first set of inflation parameters into said memory if said vehicle occupant is restrained by said seatbelt restraint;
otherwise, selecting a second set of inflation parameters if said vehicle occupant is not restrained by said seatbelt restraint, said second set of inflation parameters having a plurality of second predetermined impact magnitude thresholds; and
storing said second set of inflation parameters into said memory if said vehicle occupant is not restrained by said seatbelt restraint.
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3. The method of claim 1 wherein the step of generating at least one of said first and second squib pulses includes the steps of:
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determining whether said impact magnitude exceeds a MEDIUM impact magnitude value;
determining whether a value in said timer is less than a predetermined intermediate timer value if said impact magnitude does not exceed said MEDIUM impact magnitude value;
generating said first squib pulse if said impact magnitude exceeds said LOW impact magnitude value and said value in said timer is not less than said predetermined intermediate timer value to thereby cause said first charge to ignite and inflate said airbag at a predetermined low inflation rate;
otherwise, generating said first squib pulse to ignite said first charge if said impact magnitude exceeds said MEDIUM impact magnitude value; and
generating said second squib pulse after a predetermined amount of time to ignite said second charge to thereby cause said airbag to inflate at a predetermined intermediate inflation rate.
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4. The method of claim 3 wherein the step of determining whether said impact magnitude exceeds said MEDIUM impact magnitude value and the step of determining whether said value in said timer is less than said predetermined intermediate timer value are repeated if said impact magnitude does not exceed said MEDIUM impact magnitude value and said value in said timer is less than said predetermined intermediate timer value.
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5. The method of claim 1 wherein the step of determining whether said value in said timer is less than said predetermined high timer value and the step of determining whether said impact magnitude exceeds said HIGH impact magnitude value are repeated if said impact magnitude does not exceed said HIGH impact magnitude value and said value in said timer is less than said predetermined high timer value.
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6. The method of claim 1 further comprising the step of performing a diagnostic subroutine on said first and second squib circuits.
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7. The method of claim 6 wherein the step of performing a diagnostic subroutine includes the steps of:
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determining if said first squib circuit is operational;
setting a first squib fault flag if said first squib circuit is not operational;
determining if said second squib circuit is operational; and
setting a second squib fault flag if said second squib circuit not operational.
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8. The method of claim 6 wherein the step of generating at least one of said first and second squib pulses includes the steps of:
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determining if said impact magnitude exceeds a MEDIUM impact magnitude;
determining if said value in said timer is less than a predetermined intermediate timer value;
determining if said first squib circuit is operational;
determining if said second squib circuit is operational;
generating said first squib pulse if said impact magnitude exceeds said MEDIUM impact magnitude, said first squib circuit is operational and said second squib circuit is not operational to thereby cause said airbag to inflate at a predetermined low inflation rate;
otherwise, generating said second squib pulse if said impact magnitude exceeds said MEDIUM impact magnitude and said first squib circuit is not operational to thereby cause said airbag to inflate at a predetermined alternative low inflation rate;
otherwise, generating said first squib pulse to ignite said first charge if said impact magnitude exceeds said MEDIUM impact magnitude and said value in said timer is less than said predetermined intermediate timer value; and
generating said second squib pulse after a predetermined amount of time to ignite said second charge to thereby cause said airbag to inflate at a predetermined intermediate inflation rate.
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9. The method of claim 8 further comprising the steps of:
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generating said first squib pulse if said impact magnitude exceeds said LOW impact magnitude, said value in said timer is not less than said intermediate timer value and said first squib circuit is operational; and
otherwise, generating said second squib pulse if said impact magnitude exceeds said LOW impact magnitude, said value in said timer is not less than said intermediate timer value and said first squib circuit is not operational.
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10. The method of claim 6 wherein said diagnostic subroutine includes the steps of:
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determining if a first portion of said first squib circuit is shorted to a ground;
determining if a second portion of said first squib circuit is shorted to a vehicle power supply;
determining if said first squib circuit is open; and
determining if said first squib circuit is shorted.
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11. The method of claim 6 wherein said diagnostic subroutine includes the steps of:
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determining if a first portion of said second squib circuit is shorted to a ground;
determining if a second portion of said second squib circuit is shorted to a vehicle power supply;
determining if said second squib circuit is open; and
determining if said second squib circuit is shorted.
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12. In a vehicle having an impact sensor, a seatbelt restraint sensor, an airbag module and a control module having a memory and a timer, said impact sensor operable for generating an impact signal in response to a collision involving said vehicle, said seatbelt restraint sensor operable for generating a restraint signal indicating that a vehicle occupant is restrained by a seatbelt restraint, said airbag module including an inflator having first and second charges, first and second squib circuits and an airbag, said first squib circuit including a first squib coupled to said first charge and operable for igniting said first charge, said second squib circuit including a second squib coupled to said second charge and operable for igniting said second charge, said control module coupled to said impact sensor, said seatbelt restraint sensor and said first and second squib circuits, said control module receiving said impact signal and said restraint signal, said control module operable for selectively generating first and second squib pulses to cause said first and second squibs, respectively, to ignite said first and second charges, respectively, a method for controlling deployment of said airbag comprising the steps of:
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determining whether said vehicle occupant is restrained by said seatbelt restraint;
selecting a first set of inflation parameters if said vehicle occupant is restrained by said seatbelt restraint, said first set of inflation parameters having a plurality of first predetermined impact magnitude thresholds;
storing said first set of inflation parameters into said memory if said vehicle occupant is restrained by said seatbelt restraint;
selecting a second set of inflation parameters if said vehicle occupant is not restrained by said seatbelt restraint, said second set of inflation parameters having a plurality of second predetermined impact magnitude thresholds;
storing said second set of inflation parameters into said memory if said vehicle occupant is not restrained by said seatbelt restraint;
determining whether a collision having an impact magnitude exceeding a predetermined initial impact magnitude value has occurred;
setting said timer to zero and starting said timer;
determining whether said impact magnitude continues to exceed said initial impact magnitude;
repeating the previous eight steps if said impact magnitude does not continue to exceed said initial impact magnitude;
determining whether said impact magnitude exceeds a predetermined LOW impact magnitude value if said impact magnitude continues to exceed said initial impact magnitude;
repeating the above two steps if said impact magnitude does not exceed said LOW impact magnitude value;
determining whether a value of said timer is less than a predetermined high timer value if said impact magnitude exceeds said LOW impact magnitude value;
determining whether said impact magnitude exceeds a HIGH impact magnitude value if said timer value does not exceed said high timer value;
repeating the previous two steps if said impact magnitude does not exceed said HIGH impact magnitude value and said value in said timer is less than said predetermined high timer value;
generating said first and second squib pulses if said impact magnitude exceeds said HIGH impact magnitude value and said timer value is less than said high timer value, said first and second squib pulses thereby causing said first and second squibs, respectively, to ignite said first and second charges, respectively, and inflating said airbag at a predetermined high inflation rate; and
generating at least one of said first and second squib pulses if said impact magnitude exceeds said LOW impact magnitude value, said at least one of said first and second squib pulses thereby causing at least one of said first and second charges to ignite and inflate said airbag at an inflation rate less than said predetermined high inflation rate. - View Dependent Claims (13, 14, 15, 16, 17, 18, 19, 20)
determining whether said impact magnitude exceeds a MEDIUM impact magnitude value;
determining whether a value in said timer is less than a predetermined intermediate timer value if said impact magnitude does not exceed said MEDIUM impact magnitude value;
generating said first squib pulse if said impact magnitude exceeds said LOW impact magnitude value and said value in said timer is not less than said predetermined intermediate timer value to thereby cause said first charge to ignite and inflate said airbag at a predetermined low inflation rate;
otherwise, generating said first squib pulse to ignite said first charge if said impact magnitude exceeds said MEDIUM impact magnitude value and said value in said timer is less than said predetermined intermediate timer value; and
generating said second squib pulse after a predetermined amount of time to ignite said second charge to thereby cause said airbag to inflate at a predetermined intermediate inflation rate.
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14. The method of claim 13 wherein the step of determining whether said impact magnitude exceeds said MEDIUM impact magnitude value and the step of determining whether said value in said timer is less than said predetermined intermediate timer value are repeated if said impact magnitude does not exceed said MEDIUM impact magnitude value and said value in said timer is less than said predetermined intermediate timer value.
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15. The method of claim 12 further comprising the step of performing a diagnostic subroutine on said first and second squib circuits.
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16. The method of claim 15 wherein the step of performing a diagnostic subroutine includes the steps of:
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determining if said first squib circuit is operational;
setting a first squib fault flag if said first squib circuit is not operational;
determining if said second squib circuit is operational; and
setting a second squib fault flag if said second squib circuit not operational.
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17. The method of claim 15 wherein the step of generating at least one of aid first and second squib pulses includes the steps of:
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determining if said impact magnitude exceeds a MEDIUM impact magnitude;
determining if said value in said timer is less than a predetermined intermediate timer value;
determining if said first squib circuit is operational;
determining if said second squib circuit is operational;
generating said first squib pulse if said impact magnitude exceeds said MEDIUM impact magnitude, said first squib circuit is operational and said second squib circuit is not operational to thereby cause said airbag to inflate at a predetermined low inflation rate;
otherwise, generating said second squib pulse if said impact magnitude exceeds said MEDIUM impact magnitude and said first squib circuit is not operational to thereby cause said airbag to inflate at a predetermined alternative low inflation rate;
otherwise, generating said first squib pulse to ignite said first charge if said impact magnitude exceeds said MEDIUM impact magnitude and said value in said timer is less than said predetermined intermediate timer value; and
generating said second squib pulse after a predetermined amount of time to ignite said second charge to thereby cause said airbag to inflate at a predetermined intermediate inflation rate.
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18. The method of claim 17 further comprising the steps of:
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generating said first squib pulse if said impact magnitude exceeds said LOW impact magnitude, said value in said timer is not less than said intermediate timer value and said first squib circuit is operational; and
otherwise, generating said second squib pulse if said impact magnitude exceeds said LOW impact magnitude, said value in said timer is not less than said intermediate timer value and said first squib circuit is not operational.
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19. The method of claim 15 wherein said diagnostic subroutine includes the steps of:
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determining if a first portion of said first squib circuit is shorted to a ground;
determining if a second portion of said first squib circuit is shorted to a vehicle power supply;
determining if said first squib circuit is open; and
determining if said first squib circuit is shorted.
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20. The method of claim 15 wherein said diagnostic subroutine includes the steps of:
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determining if a first portion of said second squib circuit is shorted to a ground;
determining if a second portion of said second squib circuit is shorted to a vehicle power supply;
determining if said second squib circuit is open; and
determining if said second squib circuit is shorted.
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Specification