Method and apparatus for controlling an actuatable restraint device using crash severity indexing and crush zone sensor

• US 6,186,539 B1
• Filed: 11/20/1998
• Issued: 02/13/2001
• Est. Priority Date: 07/01/1998
• Status: Expired due to Term

• Current Assignee: TRW Inc. (Northrop Grumman Corporation)
• Original Assignee: TRW Inc. (Northrop Grumman Corporation)
• Inventors: Chiang, Wei-Te, Weiss, Kevin D., Yeh, Huahn-Fern (Jeff), Foo, Chek-Peng (Anson), Shields, Anne Marie
• Primary Examiner(s): Rice, Kenneth R.
• Application Number:
  US09/197,143
• Time in Patent Office: 816 Days
• Field of Search: 280/735, 701/45
• US Class Current: 280/735
• CPC Class Codes: B60R 2021/0004 Frontal collision
• CPC Class Codes: B60R 2021/0006 Lateral collision
• CPC Class Codes: B60R 2021/01006 Mounting of electrical components in vehicles
• CPC Class Codes: B60R 2021/0102 the monitored value being used for calculating occupant displacement
• CPC Class Codes: B60R 2021/01027 Safing sensors
• CPC Class Codes: B60R 2021/01034 Controlling a plurality of restraint devices
• CPC Class Codes: B60R 2021/01322 comprising variable thresholds, e.g. depending from other collision parameters
• 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
• CPC Class Codes: B60R 21/0136 responsive to actual contact with an obstacle , e.g. to vehicle deformation, bumper displacement or bumper velocity relative to the vehicle monitoring crash strength in combination with passenger seat detection B60R21/01558
• CPC Class Codes: B60R 21/01546 using belt buckle sensors
• CPC Class Codes: B60R 21/01558 monitoring crash strength
• CPC Class Codes: B60R 21/0156 by deceleration

Abstract

An apparatus for controlling an actuatable occupant restraint device for a vehicle (11) having first and second actuatable stages (24, 26). The apparatus includes a crash sensor (17, 19) mounted near the front of the vehicle (11) for providing a crash acceleration signal (238, 270). An average crash acceleration determiner (246, 278) determines an average crash acceleration value, and provides a signal indicative thereof. A controller (31) is operatively coupled to the actuatable stages (24, 26). The controller effects actuation of the first actuatable stage when the determined average acceleration value exceeds a first threshold value (248, 250, 254, 256). The controller (31) determines a crash severity index having a value according to a time interval from when the determined average crash acceleration value exceeds the first threshold value (248, 250, 254, 256) to when it exceeds a second threshold value (252, 258). The controller effects actuation of the second actuatable stage in response to the crash severity index value (287, 291).

Claims

1. An apparatus for controlling an actuatable occupant restraining device for a vehicle, said restraining device having a plurality of actuatable stages, said apparatus comprising:

a central crash sensor located at a substantially central location of the vehicle for sensing crash acceleration during a vehicle crash condition and providing a first crash acceleration signal indicative thereof;

velocity determining means responsive to said first crash acceleration signal for determining a crash velocity value from said first crash acceleration signal and providing a crash velocity signal indicative thereof;

crush zone sensor located at a forward location of the vehicle so as to be subjected to crash acceleration relatively early during the vehicle crash condition, said crush zone sensor providing a second crash acceleration signal indicative thereof;

control means coupled to said actuatable device, said central crash sensor, and said crush zone sensor for (i) effecting actuation of a first of said actuatable stages when said determined crash velocity value exceeds a first threshold value, (ii) effecting actuation of said first of said actuatable stages when a value functionally related to said crash acceleration value from said crush zone sensor exceeds a second threshold value, (iii) upon said determined crash velocity value exceeding a third threshold value, determining a first crash severity index having a value related to a time interval from when said determined crash velocity value exceeds said first threshold value to when said determined crash velocity value exceeds said third threshold value, and (iv) upon said determined crash acceleration from said crush zone sensor exceeding a fourth threshold value, determining a second crash severity index having a value related to a time interval from when said determined crush zone sensor crash acceleration value exceeds said second threshold value to when said determined crush zone sensor crash acceleration value exceeds said fourth threshold value, said control means controlling actuation of a second of said actuatable stages in response to one of said first and second crash severity index values.

2. The apparatus of claim 1 wherein said control means includes means for determining a crash displacement value from crash acceleration and means for varying said first, second, third, and forth threshold values in response to said determined crash displacement value.

3. The apparatus of claim 1 wherein said apparatus further comprises sensing means for sensing whether an occupant is belted or unbelted, said control means determining said crash severity indexes in response to whether the occupant is sensed as being belted or unbelted.

4. An apparatus for controlling an actuatable occupant restraint device having first and second actuatable stages, said apparatus comprising:

a crash sensor for sensing crash acceleration and providing a crash acceleration signal indicative thereof;

an average crash acceleration determiner responsive to said crash acceleration signal for determining an average crash acceleration value and providing a signal indicative thereof; and

a controller operatively coupled to said first and second actuatable stages, said controller effecting actuation of said first actuatable stage upon said determined average acceleration value exceeding a first threshold value, and said controller determining a crash severity index having a value responsive to a time interval from when said determined average crash acceleration value exceeds said first threshold value to when said determined average crash acceleration value exceeds a second threshold value, said controller effecting actuation of said second actuatable stage in response to said determined crash severity index value.

5. The apparatus of claim 4 wherein said average crash acceleration determiner determines a moving average.

6. The apparatus of claim 4 further comprising a switch for detecting a belted or unbelted occupant condition and providing a signal indicative of said detected occupant condition, actuation of said first and second actuatable stages being further responsive to said switch signal.

7. A method for controlling actuation of an actuatable occupant restraint device having a plurality of stages, said method comprising the steps of:

sensing crash acceleration at a substantially central location of the vehicle and providing a first crash acceleration signal indicative thereof;

determining a velocity value in response to said first crash acceleration signal;

sensing crash acceleration at a forward location of said vehicle and providing a second crash acceleration signal indicative thereof;

effecting actuation of a first of said actuatable stages in response to at least one said determined velocity value exceeding a first threshold value and said second acceleration signal exceeding a second threshold value;

determining at least one of a first crash severity index having a value responsive to a time interval from when said determined velocity value exceeds said first threshold value to when said determined velocity value exceeds a third threshold value, and a second crash severity index having a value responsive to the time interval from when said crash acceleration value exceeded the second threshold value to when it exceeds a fourth threshold value; and

effecting actuation of a second of said actuatable stages in response to at least one of said first and second crash severity indexes.

8. The method of claim 7 further comprising the step of adjusting at least one of said first and second crash severity indexes in response to a sensed occupant condition.