Pedestrian collision detection apparatus and pedestrian protection system

• US 7,737,833 B2
• Filed: 11/28/2007
• Issued: 06/15/2010
• Est. Priority Date: 12/11/2006
• Status: Active Grant

• Current Assignee: DENSO Corporation
• Original Assignee: DENSO Corporation
• Inventors: Takafuji, Tetsuya
• Primary Examiner(s): La; Anh V
• Application Number:
  US11/998,110
• Publication Number:
  US 20080136613A1
• Time in Patent Office: 930 Days
• Field of Search: 340/435, 340/436, 340/425.5, 340/903, 701/1, 701/45, 280/728.1, 280/734, 280/735, 180/170, 180/274, 180/271
• US Class Current: 340/436
• CPC Class Codes: B60R 19/02 Bumpers, i.e. impact receiving or absorbing members for protecting vehicles or fending off blows from other vehicles or objects B60R19/56 takes precedence; initiating brake action by contact of bumper with an external object B60T7/22; for rail vehicles B61F19/04; safety equipment for cycles B62J27/00; integral with waterborne vessels or specially adapted therefor B63B59/02
• CPC Class Codes: B60R 2021/003 characterised by occupant or pedestian
• CPC Class Codes: B60R 21/0132 responsive to vehicle motion parameters , e.g. to vehicle longitudinal or transversal deceleration or speed value
• 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

A pedestrian collision detection apparatus includes a bumper sensor, an acceleration sensor, a vehicle speed sensor, and a controller. The controller calculates an effective mass based on outputs from the bumper sensor and the speed sensor. The controller calculates a velocity change based on an output from the acceleration sensor. Further, the controller includes a two-dimensional map, which contains an effective mass and a velocity change and defines a pedestrian area for collision with a pedestrian. The controller determines a collision with a pedestrian when the pedestrian area contains a point determined by the calculated maximum effective mass and maximum velocity change. It is therefore possible to accurately distinguish a collision between the vehicle and the pedestrian from collision with the other object to reliably detect the collision.

Claims

1. A pedestrian collision detection apparatus for a vehicle, the apparatus comprising:

a bumper sensor configured to detect a deformation of a bumper of the vehicle, a load applied to the bumper, or a pressure applied to the bumper;

an acceleration sensor configured to detect an acceleration of the vehicle; and

a pedestrian collision determination unit configured to include a two-dimensional map for defining a correlation between a first parameter and a second parameter when colliding with a pedestrian, the first parameter being equivalent to a deformation of the bumper calculated based on an output from the bumper sensor, the second parameter being equivalent to an impact applied to the vehicle calculated based on an output from the acceleration sensor, and further configured to determine a collision with a pedestrian when a specified area of the two-dimensional map contains a point determined by a calculated maximum value for the first parameter and a calculated maximum value for the second parameter.

2. The pedestrian collision detection apparatus of claim 1, wherein:

the bumper sensor is a load sensor that detects a load applied to the bumper;

the first parameter is a load applied to the bumper; and

the second parameter is a vehicle velocity change due to a collision.

3. The pedestrian collision detection apparatus of claim 1, wherein:

the bumper sensor is a load sensor that detects a load applied to the bumper;

the first parameter is a mass of a colliding object; and

the second parameter is a vehicle velocity change due to a collision.

4. The pedestrian collision detection apparatus of claim 3, wherein:

the first parameter is calculated based on time integration of an output from the bumper sensor.

5. The pedestrian collision detection apparatus of claim 1, wherein:

the bumper sensor is a pressure sensor that detects a pressure applied to the bumper;

the first parameter is a pressure applied to the bumper; and

the second parameter is a vehicle velocity change due to a collision.

6. The pedestrian collision detection apparatus of claim 1, wherein:

the bumper sensor is a pressure sensor that detects a pressure applied to the bumper;

the first parameter is a mass of a colliding object; and

the second parameter is a vehicle velocity change due to a collision.

7. The pedestrian collision detection apparatus of claim 1, wherein:

the bumper sensor is a distance sensor that detects a deformation of the bumper;

the first parameter is a deformation of the bumper; and

the second parameter is a vehicle velocity change due to a collision.

8. The pedestrian collision detection apparatus of claim 1, wherein

the pedestrian collision determination unit outputs a start signal for starting a pedestrian protection apparatus when detecting a collision with a pedestrian.

9. The pedestrian collision detection apparatus of claim 8, further comprising:

a speed sensor for detecting a speed of the vehicle, wherein

the pedestrian collision determination unit determines a collision with a pedestrian when a speed detected by the speed sensor belongs to a specified range.

10. The pedestrian collision detection apparatus of claim 1, wherein

the second parameter is calculated based on time integration of an output from the acceleration sensor.

11. The pedestrian collision detection apparatus of claim 1, wherein

the pedestrian collision determination unit determines a collision with a pedestrian when at least one of the first and second parameters is maximized and then decreases to a value indicative of a specified ratio to the maximum value.

12. A pedestrian protection system comprising:

the pedestrian collision detection apparatus of claim 1; and

a pedestrian protection apparatus.

13. A pedestrian collision detection apparatus for a vehicle, the apparatus comprising:

a bumper sensor configured to detect a load or a pressure applied to a bumper of the vehicle;

a speed sensor configured to detect a speed of the vehicle;

an acceleration sensor configured to detect an acceleration of the vehicle; and

a pedestrian collision determination unit configured to include a two-dimensional map for defining a correlation between a first parameter and a second parameter when colliding with a pedestrian, the first parameter being equivalent to a deformation of the bumper calculated based on outputs from the bumper sensor and the vehicle speed sensor, the second parameter being equivalent to an impact applied to the vehicle calculated based on an output from the acceleration sensor, and further configured to determine a collision with a pedestrian when a specified area of the two-dimensional map contains a point determined by a calculated maximum value for the first parameter and a calculated maximum value for the second parameter.

14. The pedestrian collision detection apparatus of claim 13, wherein:

the bumper sensor is a load sensor that detects a load applied to the bumper;

the first parameter is a mass of an object colliding with the bumper; and

the second parameter is a vehicle velocity change due to a collision.

15. The pedestrian collision detection apparatus of claim 14, wherein

the first parameter is calculated based on (i) an integration value resulting from time integration of an output from the bumper sensor and (ii) an output from the speed sensor.

16. The pedestrian collision detection apparatus of claim 13, wherein:

the bumper sensor is a pressure sensor that detects a pressure applied to the bumper;

the first parameter is a mass of a colliding object; and

the second parameter is a vehicle velocity change due to a collision.

17. The pedestrian collision detection apparatus of claim 13, wherein

the pedestrian collision determination unit outputs a start signal for starting a pedestrian protection apparatus when detecting a collision with a pedestrian.

18. The pedestrian collision detection apparatus of claim 13, wherein

the pedestrian collision determination unit determines a collision with a pedestrian when a speed of the vehicle detected by the speed sensor belongs to a specified range.

19. The pedestrian collision detection apparatus of claim 13, wherein

the second parameter is calculated based on time integration of an output from the acceleration sensor.

20. The pedestrian collision detection apparatus of claim 13, wherein

the pedestrian collision determination unit determines a collision with a pedestrian when at least one of the first and second parameters is maximized and then decreases to a value indicative of a specified ratio to the maximum value.

21. A pedestrian protection system comprising:

the pedestrian collision detection apparatus of claim 13; and

a pedestrian protection apparatus.