Dual stage occupant restraint deployment control for motor vehicle
First Claim
1. A method for controlling the deployment of a dual stage occupant restraint in a motor vehicle comprising the steps:
- sensing a possible crash event;
sensing a vehicle acceleration and deriving therefrom an acceleration signal;
deriving a velocity signal from the acceleration signal;
deriving one or more immunity measures for indicating non-crash events;
generating a first stage activation signal if the velocity value and all derived immunity measures meet predetermined criteria during the sensed possible crash event;
deriving a crash severity measure from the acceleration signal, the crash severity measure not being immune from accelerations due to non-crash events; and
generating a second stage activation signal in response to the crash severity measure meeting predetermined criteria if the first stage activation signal has been generated.
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Accused Products
Abstract
A dual stage occupant restraint deployment control provides a signal for first stage restraint deployment if, during a sensed possible crash event, a velocity value derived from a sensed acceleration and one or more immunity measures meet predetermined criteria. A second stage restraint deployment signal is provided if a crash severity measure derived from the time rate of change of the sensed acceleration meets predetermined criteria and the first stage activation signal has been generated. The method and apparatus ensure that the immunity criteria are met for both first and second stage deployment without repeated testing if the crash severity measure is vulnerable to non-crash accelerations produced by “misuse” events and rough road driving. The crash severity measure may be the time rate of change of the acceleration itself, an oscillation value derived this time rate of change of the acceleration with a velocity value requirement in the predetermined criteria, or a veloscillation value derived as a scaled sum of the oscillation value and the velocity value.
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Citations
19 Claims
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1. A method for controlling the deployment of a dual stage occupant restraint in a motor vehicle comprising the steps:
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sensing a possible crash event;
sensing a vehicle acceleration and deriving therefrom an acceleration signal;
deriving a velocity signal from the acceleration signal;
deriving one or more immunity measures for indicating non-crash events;
generating a first stage activation signal if the velocity value and all derived immunity measures meet predetermined criteria during the sensed possible crash event;
deriving a crash severity measure from the acceleration signal, the crash severity measure not being immune from accelerations due to non-crash events; and
generating a second stage activation signal in response to the crash severity measure meeting predetermined criteria if the first stage activation signal has been generated. - View Dependent Claims (2, 3, 4, 5, 6, 7, 8, 9)
deploying a first stage of the dual stage occupant restraint in response to the first stage activation signal; and
deploying a second stage of the dual stage occupant restraint in response to the second stage activation signal.
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10. A method for controlling the deployment of an occupant restraint in a motor vehicle comprising the steps:
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sensing a possible crash event;
sensing a vehicle acceleration and deriving therefrom an acceleration signal;
deriving a velocity signal from the acceleration signal;
deriving a crash severity measure as the scaled sum of (1) an oscillation value derived from the time integral of the absolute value of the time derivative of the acceleration and (2) the value of the velocity signal. - View Dependent Claims (11, 12, 13, 14)
deriving a slope value as the difference between consecutive acceleration signals; and
deriving the time derivative of the acceleration signal as an accumulation of the absolute values of consecutive slope values.
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14. The method of claim 13 in which the crash severity measure is derived by register shifting the derived velocity signal to obtain a scaled velocity signal and summing the scaled velocity signal with the oscillation signal.
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15. Apparatus for controlling the deployment of a dual stage occupant restraint in a motor vehicle comprising:
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means for sensing a possible crash event;
means for deriving a vehicle acceleration signal;
means for deriving a velocity signal from the vehicle acceleration signal;
means for deriving one or more immunity measures for indicating non-crash events;
means for generating a first stage activation signal if the velocity value and all derived immunity measures meet predetermined criteria during the sensed possible crash event;
means for deriving a crash severity measure from the acceleration signal, the crash severity measure not being immune from accelerations due to non-crash events; and
means for generating a second stage activation signal in response to the crash severity measure meeting predetermined criteria if the first stage activation signal has been generated. - View Dependent Claims (16, 17, 18, 19)
means for deploying a first stage of the dual stage occupant restraint in response to the first stage activation signal, and means for deploying a second stage of the dual stage occupant restraint in response to the second stage activation signal.
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17. Apparatus according to claim 15 further comprising means for deriving the crash severity measure from a time rate of change of the sensed acceleration.
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18. Apparatus according to claim 17 in which the crash severity measure is derived from (1) an oscillation value derived from the time integral of the absolute value of the time derivative of the acceleration and (2) the value of the velocity signal.
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19. Apparatus according to claim 18 in which the crash severity measure is a scaled sum of the oscillation value and the value of the velocity signal.
Specification