Frontal impact characterization apparatus for a motor vehicle restraint system

• US 6,559,763 B2
• Filed: 04/23/2001
• Issued: 05/06/2003
• Est. Priority Date: 04/23/2001
• Status: Expired due to Term

• Current Assignee: Aptiv Technologies Limited (BorgWarner Incorporated)
• Original Assignee: Delphi Technologies, Inc. (BorgWarner Incorporated)
• Inventors: Cluff, Charles A., Little, David R., Oberlin, Gary Eugene, McCoy, Greston T. Jr., Nunan, Douglas Allen, Murphy, Morgan D.
• Primary Examiner(s): Wu, Daniel J.
• Assistant Examiner(s): Nguyen, Phung
• Application Number:
  US09/840,553
• Publication Number:
  US 20020154006A1
• Time in Patent Office: 743 Days
• Field of Search: 340/436, 340/438, 340/665, 280/735, 737/21, 701/70, 701/300, 701/301
• US Class Current: 340/436
• CPC Class Codes: B60R 2021/0004 Frontal collision
• 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

Abstract

An improved vehicle crash sensing apparatus quickly and reliably characterizes frontal impacts with only minimal data processing requirements. Two or more longitudinally separated piezoelectric strips strategically located in a frontal portion of the vehicle produce impact signals that are analyzed to characterize the type of impact and the structural crush rate. In a simple implementation involving only two piezoelectric strips, a first strip extends laterally along a forward portion of the front bumper, and a second strip extends laterally along a forward portion of the hood panel, above and rearward of the first strip. In cases where an impact signal is developed by only one of the two strips, a high (under-ride) or low (over-ride) impact is indicated. If impact signals are developed by both strips, the intervening time is measured as an indication of the structural crush rate. In a more complex implementation, the bumper and hood strips are divided into two or more individual strip segments so the center and distribution of impact and the impact vector may be quickly and reliably characterized as well.

Claims

1. Crash sensing apparatus for a vehicle comprising:

first and second piezoelectric strips affixed to the vehicle for producing first and second crash intensity signals in relation to mechanical energy applied to said strips upon initiation of a vehicle crash event, such first and second strips extending laterally across a frontal portion of the vehicle, with both longitudinal and vertical separation between said first and second strips; and

a signal processor for receiving the first and second crash intensity signals and characterizing the crash by comparing the first and second crash intensity signals to first and second thresholds, and calculating a crush rate of the vehicle based on an elapsed time between the first crash intensity signal reaching the first threshold, and the second crash intensity signal reaching the second threshold.

2. Crash sensing apparatus for a vehicle comprising:

first and second piezoelectric strips affixed to the vehicle for producing first and second crash intensity signals in relation to mechanical energy applied to said strips upon initiation of a vehicle crash event, the first strip being affixed to a leading edge of a front bumper of the vehicle, and the second strip being affixed to a hood panel above and rearward of the first piezoelectric strip; and

a signal processor for receiving the first and second crash intensity signals, comparing the first and second crash intensity signals to first and second thresholds, and characterizing the crash event as an over-ride event if the first crash intensity signal fails to reach the first threshold within a predefined time period after the second crash intensity signal reaches the second threshold.

3. Crash sensing apparatus for a vehicle comprising:

first and second piezoelectric strips affixed to the vehicle for producing first and second crash intensity signals in relation to mechanical energy applied to said strips upon initiation of a vehicle crash event, the first strip being affixed to a leading edge of a front bumper of the vehicle, and the second strip being affixed to a hood panel above and rearward of the first piezoelectric strip; and

a signal processor for receiving the first and second crash intensity signals, comparing the first and second crash intensity signals to first and second thresholds, and characterizing the crash event as an under-ride event if the second crash intensity signal fails to reach the second threshold within a predefined time period after the first crash intensity signal reaches the first threshold.

4. Crash sensing apparatus for a vehicle comprising:

first and second piezoelectric strips extending laterally across a frontal portion of the vehicle for producing first and second crash intensity signals in relation to mechanical energy applied to said strips upon initiation of a vehicle crash event, at least one of the first and second piezoelectric strips being defined by a plurality of linearly aligned piezoelectric segments that produce individual crash intensity signals, and

a signal processor for receiving the first and second crash intensity signals, and characterizing the crash event by computing a center of contact signal based on such individual crash intensity signals.

5. Crash sensing apparatus for a vehicle comprising:

first and second piezoelectric strips extending laterally across a frontal portion of the vehicle for producing first and second crash intensity signals in relation to mechanical energy applied to said strips upon initiation of a vehicle crash event, at least one of the first and second piezoelectric strips being defined by a plurality of linearly aligned piezoelectric segments that produce individual crash intensity signals, and

a signal processor for receiving the first and second crash intensity signals, and characterizing the crash event by computing a sum of the individual crash intensity signals and a plurality of contact distribution signals corresponding to a contribution of each of the individual crash intensity signals to such sum.

6. Crash sensing apparatus for a vehicle comprising:

first and second longitudinally displaced piezoelectric strips extending laterally across a frontal portion of the vehicle for producing first and second crash intensity signals in relation to mechanical energy applied to said strips upon initiation of a vehicle crash event, such first and second strips, said first and second piezoelectric strips each being defined by a plurality of linearly aligned piezoelectric segments that produce individual crash intensity signals, and

a signal processor for receiving the first and second crash intensity signals, and characterizing the crash event by computing a center of contact signal for both the first and second piezoelectric strips based on respective individual crash intensity signals, and determining a collision vector of the crash event based on the computed centers of contact.

7. A vehicle occupant restraint system having occupant restraints and a controller for deploying one or more of the restraints based on input signals indicative of intensity of a crash event, the improvement wherein:

first and second input signals are developed by first and second piezoelectric strips extending laterally across a frontal portion of the vehicle, with both longitudinal and vertical separation between said first and second strips; and

a signal processor characterizes the crash event based on the first and second input signals as part of a decision making process used to trigger deployment of said occupant restraints by comparing the first and second input signals to first and second thresholds, and calculating a crush rate of the vehicle based on an elapsed time between the first input signal reaching the first threshold, and the second input signal reaching the second threshold.

8. A vehicle occupant restraint system having occupant restraints and a controller for deploying one or more of the restraints based on input signals indicative of intensity of a crash event, the improvement wherein:

first and second input signals are developed by first and second piezoelectric strips, the first strip being affixed to a leading edge of a front bumper of the vehicle, and the second strip being affixed to a hood panel above and rearward of the first piezoelectric strip; and

a signal processor characterizes the crash event based on the first and second input signals as part of a decision making process used to trigger deployment of said occupant restraints by comparing the first and second input signals to first and second thresholds, and characterizing the crash event as an over-ride event if the first input signal fails to reach the first threshold within a predefined time period after the second input signal reaches the second threshold.

9. A vehicle occupant restraint system having occupant restraints and a controller for deploying one or more of the restraints based on input signals indicative of intensity of a crash event, the improvement wherein:

first and second input signals are developed by first and second piezoelectric strips, the first strip being affixed to a leading edge of a front bumper of the vehicle, and the second strip being affixed to a hood panel above and rearward of the first piezoelectric strip; and

a signal processor characterizes the crash event based on the first and second input signals as part of a decision making process used to trigger deployment of said occupant restraints by comparing the first and second input signals to first and second thresholds, and characterizing the crash event as an under-ride event if the second input signal fails to reach the second threshold within a predefined time period after the first input signal reaches the first threshold.

10. A vehicle occupant restraint system having occupant restraints and a controller for deploying one or more of the restraints based on input signals indicative of intensity of a crash event, the improvement wherein:

first and second input signals are developed by first and second piezoelectric strips extending laterally across a frontal portion of the vehicle, at least one of the first and second piezoelectric strips being defined by a plurality of linearly aligned piezoelectric segments that produce individual input signals, and

a signal processor characterizes the crash event based on the first and second input signals as part of a decision making process used to trigger deployment of said occupant restraints by computing a center of contact signal based on such individual input signals.

11. A vehicle occupant restraint system having occupant restraints and a controller for deploying one or more of the restraints based on input signals indicative of intensity of a crash event, the improvement wherein:

first and second input signals are developed by first and second piezoelectric strips extending laterally across a frontal portion of the vehicle, at least one of the first and second piezoelectric strips being defined by a plurality of linearly aligned piezoelectric segments that produce individual input signals, and

a signal processor characterizes the crash event based on the first and second input signals as part of a decision making process used to trigger deployment of said occupant restraints by computing a sum of the individual input signals and a plurality of contact distribution signals corresponding to a contribution of each of the individual input signals to such sum.

12. A vehicle occupant restraint system having occupant restraints and a controller for deploying one or more of the restraints based on input signals indicative of intensity of a crash event, the improvement wherein:

first and second input signals are developed by first and second longitudinally displaced piezoelectric strips extending laterally across a frontal portion of the vehicle, said first and second piezoelectric strips each being defined by a plurality of linearly aligned piezoelectric segments that produce individual input signals, and

a signal processor characterizes the crash event based on the first and second input signals as part of a decision making process used to trigger deployment of said occupant restraints by computing a center of contact signal for both the first and second piezoelectric strips based on respective individual input signals, and determining a collision vector of the crash event based on the computed centers of contact.