Pedestrian impact sensing apparatus for a vehicle bumper

• US 20070090931A1
• Filed: 09/28/2005
• Published: 04/26/2007
• Est. Priority Date: 09/28/2005
• Status: Active Grant

• Current Assignee: Delphi Technologies, Inc. (BorgWarner Incorporated)
• Original Assignee: Delphi Technologies, Inc. (BorgWarner Incorporated)
• Inventors: Hawes, Kevin, Murphy, Morgan
• Granted Patent: US 7,331,415 B2
• Time in Patent Office: Days
• US Class Current: 340/436
• 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 impact sensing apparatus includes a laterally extending air channel within a block of foam or other crushable medium disposed between a bumper fascia and a rigid bumper frame element, and one or more airflow sensors for detecting airflow within the air channel. The air channel may be defined by a flexible hollow tube embedded within the crushable medium or by a molded-in air cavity in cases where the crushable medium is formed by molding. The measured airflow provides a measure of crush rate, and two or more airflow sensors may be distributed within the air channel to optimize impact detection response time and to identify the impact location.

Claims

1. Apparatus for sensing an impact with a vehicle, comprising:

a crushable medium disposed between a vehicle body panel and a rigid frame element extending substantially parallel to said body panel;

an air channel in said crushable medium;

an airflow sensor responsive to airflow within said air channel; and

signal processing means for processing a signal produced by said airflow sensor to detect a body panel impact that displaces air within said air channel.

2. The apparatus of claim 1, where said vehicle body panel is a bumper fascia.

3. The apparatus of claim 2, wherein said signal processing means processes said signal to detect pedestrian impacts with said bumper fascia.

4. The apparatus of claim 3, wherein said signal processing means processes said signal to determine a crush rate of said crushable medium due to said impact.

5. The apparatus of claim 1, where said crushable medium is molded foam, and said air channel is a molded-in void formed in said crushable medium.

6. The apparatus of claim 1, where said air channel is defined by a flexible hollow tube extending through said crushable medium.

7. The apparatus of claim 1, comprising:

a first airflow sensor responsive to airflow in a first end of said air channel; and

a second airflow sensor responsive to airflow in a second end of said air channel.

8. The apparatus of claim 7, where said signal processing means processes signals produced by said first and second airflow sensors to detect said impact and a location of said impact.

9. The apparatus of claim 1, comprising:

a first airflow sensor responsive to airflow in a first end of said air channel;

a second airflow sensor responsive to airflow in a second end of said air channel; and

a third airflow sensor responsive to airflow substantially at a midpoint of said air channel.

10. The apparatus of claim 9, where said signal processing means processes signals produced by said first, second and third airflow sensors to detect said impact and a location of said impact.

11. The apparatus of claim 1, comprising:

first and second airflow sensors responsive to airflow at first and second locations in said air channel near a midpoint of said air channel.

12. The apparatus of claim 1, where said air channel is positioned within said crushable medium to vary a sensitivity of said apparatus to said impact.

13. The apparatus of claim 1, where said airflow sensor includes a heated element disposed in said air channel.

14. The apparatus of claim 1, where said airflow sensor includes restricted and unrestricted passages aligned with an airflow in said air channel, and a differential pressure sensor responsive to a pressure difference between said restricted and unrestricted passages.

15. The apparatus of claim 1, wherein said airflow sensor is a Pitot tube sensor disposed in said air channel.