Activation device for occupant protection apparatus and method for activating the occupant protection apparatus

• US 8,370,026 B2
• Filed: 03/04/2010
• Issued: 02/05/2013
• Est. Priority Date: 03/06/2009
• Status: Expired due to Fees

• Current Assignee: DENSO Corporation
• Original Assignee: DENSO Corporation
• Inventors: Kondoh, Toshihide, Noguchi, Takashi
• Primary Examiner(s): Zeender, Ryan
• Assistant Examiner(s): CHEIN, ALLEN C
• Application Number:
  US12/660,823
• Publication Number:
  US 20100228445A1
• Time in Patent Office: 1,069 Days
• Field of Search: 340/436, 180/271, 180/274, 180/281, 180/282, 701/45
• US Class Current: 701/45
• CPC Class Codes: B60R 2021/0004 Frontal collision
• CPC Class Codes: B60R 2021/0011 Rear collision or recoiling bounce after frontal collision
• CPC Class Codes: B60R 2021/01322 comprising variable thresholds, e.g. depending from other collision parameters
• 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 21/01332 by frequency or waveform analysis
• 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 activation device is configured to activate a protection apparatus for protecting an occupant. The activation device includes a front collision detection unit and a rear collision detection unit. The front collision detection unit outputs a front-collision-state activation signal to a front-collision protection apparatus so as to activate the front-collision protection apparatus when detecting front collision of the vehicle. The rear collision detection unit outputs a rear-collision-state activation signal to a rear-collision protection apparatus so as to activate the rear-collision protection apparatus when detecting rear collision of the vehicle. The rear collision detection unit prohibits output of the rear-collision-state activation signal to the rear-collision protection apparatus for a first period when the front collision detection unit detects front collision of the vehicle.

Claims

1. An activation device for detecting a collision of a vehicle and activating a protection apparatus for protecting an occupant, the activation device comprising:

a front collision detection unit configured to

detect a front collision of the vehicle and

output a front-collision-state activation signal to a protection apparatus related to the front collision so as to activate the protection apparatus related to the front collision when detecting the front collision; and

a rear collision detection unit configured to

detect a rear collision of the vehicle,

output a rear-collision-state activation signal to a protection apparatus related to the rear collision so as to activate the protection apparatus related to the rear collision when detecting the rear collision,

prohibit output of the rear-collision-state activation signal to the protection apparatus related to rear collision for a first predetermined period when the front collision detection unit detects the front collision, and

set a first rear collision threshold and a second rear collision threshold, which are for determining whether the vehicle causes the rear collision, respectively to a third rear collision threshold and a fourth rear collision threshold, which are less than the first rear collision threshold and the second rear collision threshold respectively, in a second predetermined period subsequent to elapse of the first predetermined period;

wherein

the first and second predetermined periods are shorter than a time period between the front collision and an expected subsequent rear collision.

2. The activation device according to claim 1, further comprising:

a collision detection unit configured to

obtain acceleration in a front direction of the vehicle as a front acceleration detection result and

obtain acceleration in a rear direction of the vehicle as a rear acceleration detection result,

wherein the front collision detection unit is further configured to

receive the front acceleration detection result from the collision detection unit and the rear acceleration detection result, and

determine whether the front acceleration detection result is greater than a first front collision threshold and determine whether the rear acceleration detection result is greater than a second front collision threshold so as to determine whether the vehicle causes the front collision,

wherein the rear collision detection unit is further configured to

receive the front acceleration detection result from the collision detection unit and the rear acceleration detection result, and

determine whether the front acceleration detection result is greater than the first rear collision threshold and determine whether the rear acceleration detection result is greater than the second rear collision threshold so as to determine whether the vehicle causes the rear collision.

3. The activation device according to claim 1, wherein the rear collision detection unit is further configured to ease detection of rear collision of the vehicle in the second predetermined period subsequent to elapse of the first predetermined period.

4. The activation device according to claim 3,

wherein the rear collision detection unit is further configured to

change the first rear collision threshold and the second rear collision threshold, such that

the front acceleration detection result easily exceeds the first rear collision threshold, and

the rear acceleration detection result easily exceeds the second rear collision threshold.

5. The activation device according to claim 1, wherein the protection apparatus related to the rear collision is at least one of an active headrest and a rear window curtain airbag.

6. The activation device according to claim 1, wherein the rear collision detection unit is further configured to set the first predetermined period to be shorter than a time period between the front collision and the rear collision, which is expected to be caused subsequent to the front collision.

7. An activation device for detecting collision of a vehicle and activating a protection apparatus for protecting an occupant, the activation device comprising:

a front collision detection unit configured to

detect a front collision of the vehicle and

output a front-collision-state activation signal to a protection apparatus related to the front collision so as to activate the protection apparatus related to the front collision when detecting the front collision;

a rear collision detection unit configured to

detect a rear collision of the vehicle,

output a rear-collision-state activation signal to a protection apparatus related to the rear collision so as to activate the protection apparatus related to the rear collision when detecting the rear collision, and

ease detection of the rear collision for a predetermined period when the front collision detection unit detects front collision;

a collision detection unit configured to

obtain acceleration in a front direction of the vehicle as a front acceleration detection result and

obtain acceleration in a rear direction of the vehicle as a rear acceleration detection result,

wherein the front collision detection unit is further configured to

receive the front acceleration detection result from the collision detection unit and the rear acceleration detection result,

determine whether the front acceleration detection result is greater than a first front collision threshold and determine whether the rear acceleration detection result is greater than a second front collision threshold so as to determine whether the vehicle causes the front collision,

wherein the rear collision detection unit is further configured to

receive the front acceleration detection result from the collision detection unit and the rear acceleration detection result,

determine whether the front acceleration detection result is greater than a first rear collision threshold and determine whether the rear acceleration detection result is greater than a second rear collision threshold so as to determine whether the vehicle causes the rear collision,

wherein the rear collision detection unit is further configured to

change the first rear collision threshold and the second rear collision threshold, when the front collision detection unit detects the front collision, such that

the front acceleration detection result easily exceeds the first rear collision threshold, and

the rear acceleration detection result easily exceeds the second rear collision threshold;

wherein

the predetermined period is shorter than a time period between the front collision and an expected subsequent rear collision.

8. The activation device according to claim 7, wherein the protection apparatus related to the rear collision is at least one of an active headrest and a rear window curtain airbag.

9. The activation device according to claim 7, wherein the rear collision detection unit is further configured to

set, when the front collision detection unit detects the front collision, a first predetermined period to be shorter than a time period between the front collision and the rear collision, which is expected to be caused subsequent to the front collision;

and

change the first rear collision threshold and the second rear collision threshold in the first predetermined period.

10. A method for activating a protection apparatus for protecting an occupant, the method comprising:

detecting a front collision of the vehicle;

detecting a rear collision of the vehicle;

outputting a front-collision-state activation signal to a protection apparatus related to the front collision so as to activate the protection apparatus related to the front collision when detecting the front collision;

outputting a rear-collision-state activation signal to a protection apparatus related to the rear collision so as to activate the protection apparatus related to the rear collision when detecting the rear collision and when the outputting is not prohibited;

prohibiting the outputting of the rear-collision-state activation signal for a first predetermined period when detecting the front collision; and

setting a first rear collision threshold and a second rear collision threshold, which are for determining whether the vehicle causes the rear collision, respectively to a third rear collision threshold and a fourth rear collision threshold, which are less than the first rear collision threshold and the second rear collision threshold, respectively, in a second predetermined period subsequent to elapse of the first predetermined period;

wherein

the first and second predetermined periods are shorter than a time period between the front collision and an expected subsequent rear collision.

11. The method according to claim 10, further comprising:

setting the first predetermined period to be shorter than a time period between the front collision and the rear collision, which is expected to be caused subsequent to the front collision.

12. A method for activating a protection apparatus for protecting an occupant, the method comprising:

detecting a front collision of the vehicle;

detecting a rear collision of the vehicle;

outputting a front-collision-state activation signal to a protection apparatus related to the front collision so as to activate the protection apparatus related to the front collision when detecting the front collision;

outputting a rear-collision-state activation signal to a protection apparatus related to the rear collision so as to activate the protection apparatus related to the rear collision when detecting the rear collision;

easing detection of the rear collision of the vehicle for a predetermined period when detecting the front collision

obtaining acceleration in a front direction of the vehicle as a front acceleration detection result;

obtaining acceleration in a rear direction of the vehicle as a rear acceleration detection result;

receiving the front acceleration detection result and the rear acceleration detection result;

determining whether the front acceleration detection result is greater than a first front collision threshold and determining whether the rear acceleration detection result is greater than a second front collision threshold so as to determine whether the vehicle causes the front collision;

determining whether the front acceleration detection result is greater than a first rear collision threshold and determining whether the rear acceleration detection result is greater than a second rear collision threshold so as to determine whether the vehicle causes the rear collision;

changing the first rear collision threshold and the second rear collision threshold, on detection of front collision, such that

the front acceleration detection result easily exceeds the first rear collision threshold, and

the rear acceleration detection result easily exceeds the second rear collision threshold;

wherein

the predetermined period is shorter than a time period between the front collision and an expected subsequent rear collision.

13. The method according to claim 12, further comprising:

setting, on detection of the front collision, a first predetermined period to be shorter than a time period between the front collision and the rear collision, which is expected to be caused subsequent to the front collision; and

changing the first rear collision threshold and the second rear collision threshold in the first predetermined period.

14. An activation device for detecting collision of a vehicle and activating a protection apparatus for protecting an occupant, the activation device comprising:

a front collision detection unit configured to

detect a front collision of the vehicle and

output a front-collision-state activation signal to a protection apparatus related to the front collision so as to activate the protection apparatus related to the front collision when detecting the front collision;

a rear collision detection unit configured to

detect a rear collision of the vehicle,

output a rear-collision-state activation signal to a protection apparatus related to the rear collision so as to activate the protection apparatus related to the rear collision when detecting the rear collision,

prohibit output of the rear-collision-state activation signal to the protection apparatus related to rear collision for a first predetermined period when the front collision detection unit detects the front collision, and

ease detection of the rear collision for a second predetermined period when the front collision detection unit detects front collision;

a collision detection unit configured to

obtain acceleration in a front direction of the vehicle as a front acceleration detection result and

obtain acceleration in a rear direction of the vehicle as a rear acceleration detection result,

wherein the front collision detection unit is further configured to

receive the front acceleration detection result from the collision detection unit and the rear acceleration detection result,

determine whether the front acceleration detection result is greater than a first front collision threshold and determine whether the rear acceleration detection result is greater than a second front collision threshold so as to determine whether the vehicle causes the front collision,

wherein the rear collision detection unit is further configured to

receive the front acceleration detection result from the collision detection unit and the rear acceleration detection result,

determine whether the front acceleration detection result is greater than a first rear collision threshold and determine whether the rear acceleration detection result is greater than a second rear collision threshold so as to determine whether the vehicle causes the rear collision,

wherein the rear collision detection unit is further configured to

change the first rear collision threshold and the second rear collision threshold, when the front collision detection unit detects the front collision, such that

the front acceleration detection result easily exceeds the first rear collision threshold, and

the rear acceleration detection result easily exceeds the second rear collision threshold;

wherein

the first and second predetermined periods are shorter than a time period between the front collision and an expected subsequent rear collision.