Method and apparatus for detecting a pedestrian impact

• US 20070027584A1
• Filed: 07/26/2005
• Published: 02/01/2007
• Est. Priority Date: 07/26/2005
• Status: Active Grant

• Current Assignee: Aptiv Technologies AG (Aptiv PLC)
• Original Assignee: Delphi Technologies, Inc. (BorgWarner Incorporated)
• Inventors: Kincaid, Kevin, Hau, Lawrence
• Granted Patent: US 7,415,337 B2
• Time in Patent Office: Days
• US Class Current: 701/1
• 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 21/34 Protecting non-occupants of a vehicle, e.g. pedestrians B60R19/02 takes precedence

Abstract

The collision of a vehicle with a pedestrian is detected based on the response of bend sensor segments affixed to a vehicle body panel such as a bumper fascia. The sensor data is processed to identify the location of an object impacting the body panel, and is correlated with calibration data to determine the shape and mass of the object. Impacts with pedestrians are discriminated from impacts with other objects based on the determined shape and mass.

Claims

1. A method of detecting an impact of a vehicle with a pedestrian, comprising the steps of:

sensing deflections of a vehicle body panel at distributed locations of said body panel;

collecting and storing the sensed deflections during impacts between said body panel and diversely shaped test objects to form a body of baseline calibration data;

detecting an impact between said body panel and an unknown object when the deflection sensed at one or more of said distributed locations exceeds a threshold;

correlating the sensed deflections due to the detected impact with the body of baseline calibration data to determine a shape of said unknown object; and

determining if said unknown object is a pedestrian based in part on the determined shape.

2. The method of claim 1, wherein:

the impacts between said body panel and said diversely shaped test objects occur at two or more different impact speeds; and

the baseline calibration data is categorized by both test object shape and impact speed.

3. The method of claim 2, including the steps of:

determining an impact speed between said body panel and said unknown object;

retrieving baseline calibration data corresponding to the determined impact speed; and

correlating the sensed deflections due to the detected impact with the retrieved baseline calibration data to determine the shape of said unknown object.

4. The method of claim 3, including the steps of:

determining a speed of said vehicle when said impact is detected; and

determining said impact speed according to the determined vehicle speed.

5. The method of claim 1, wherein:

the impacts between said body panel and said diversely shaped test objects occur at said distributed locations; and

the baseline calibration data is categorized by both impact location and test object shape.

6. The method of claim 5, including the steps of:

identifying a location of peak deflection of said body panel based on the sensed deflections;

determining a location of the impact between said body panel and said unknown object based on the identified location of peak deflection;

retrieving baseline calibration data corresponding to the determined impact location; and

correlating the sensed deflections due to the detected impact with the retrieved baseline calibration data to determine the shape of said unknown object.

7. The method of claim 1, wherein:

the impacts between said body panel and said diversely shaped test objects occur at said distributed locations and at two or more different impact speeds; and

the baseline calibration data is categorized by impact location, test object shape and impact speed.

8. The method of claim 7, including the steps of:

identifying a location of peak deflection of said body panel based on the sensed deflections;

determining a location of the impact between said body panel and said unknown object based on the identified location of peak deflection;

determining an impact speed between said body panel and said unknown object;

retrieving baseline calibration data corresponding to the determined impact location and the determined impact speed; and

correlating the sensed deflections due to the detected impact with the retrieved baseline calibration data to determine the shape of said unknown object.

9. The method of claim 1, wherein:

said diversely shaped test objects additionally vary in mass; and

the baseline calibration data is categorized by both test object mass and test object shape.

10. The method of claim 9, including the steps of:

retrieving baseline calibration data corresponding to the determined shape of said unknown object;

correlating the sensed deflections due to the detected impact with the retrieved baseline calibration data to estimate a mass of said unknown object; and

determining if said unknown object is a pedestrian based in part on the estimated mass.

11. The method of claim 1, wherein:

the impacts between said body panel and said diversely shaped test objects occur at said distributed locations; and

the body of calibration data for each such impact includes the sensed deflection at an impact location and relative deflections sensed at locations other than said impact location.

12. Apparatus for detecting an impact of a vehicle with a pedestrian, comprising:

a set of sensor segments affixed to distributed locations of a vehicle body panel to measure deflection of said body panel at said distributed locations;

a memory unit for storing a body of baseline calibration data obtained from signals produced by the sensor segments during impacts between said body panel and diversely shaped test objects; and

processing means for sampling signals produced by said sensor segments when an object is impacted by said body panel, correlating the sampled signals with the body of baseline calibration data to determine a shape of the object impacted by said body panel, and determining if the object impacted by said body panel is a pedestrian based in part on the determined shape.

13. The apparatus of claim 12, wherein:

said body panel is a bumper or bumper fascia of said vehicle.

14. The apparatus of claim 12, wherein:

the body of baseline calibration data is obtained from signals produced by the sensor segments during impacts at different speeds between said body panel and said diversely shaped test objects; and

the processing means retrieves baseline calibration data for correlation with said sampled signals based on a determined speed of impact between said object and said body panel.

15. The apparatus of claim 12, wherein:

the body of baseline calibration data is obtained from signals produced by the sensor segments during impacts at said distributed locations of said body panel; and

the processing means determines a location of impact between said object and said body panel based on the sampled signals, and retrieves baseline calibration data for correlation with said sampled signals based on the determined location of impact.

16. The apparatus of claim 12, wherein:

said diversely shaped test objects additionally vary in mass so that said body of baseline calibration data is categorized by both object shape and object mass; and

the processing means retrieves baseline calibration data for correlation with said sampled signals based on the determined shape of the object impacted by said body panel to estimate a mass of the object impacted by said body panel, and determines if the object impacted by said body panel is a pedestrian based in part on the estimated mass.