Occupant restraint system and method for restraining occupant in seat of vehicle

• US 20070017726A1
• Filed: 07/24/2006
• Published: 01/25/2007
• Est. Priority Date: 07/25/2005
• Status: Active Grant

• Current Assignee: Honda Motor Co., Ltd. (Honda Motor Company)
• Original Assignee: Honda Motor Co., Ltd. (Honda Motor Company)
• Inventors: Takemura, Naotoshi
• Granted Patent: US 7,686,340 B2
• Time in Patent Office: Days
• US Class Current: 180/268
• CPC Class Codes: B60R 16/0233 Vehicle tilting, overturning or roll over
• CPC Class Codes: B60R 2021/0018 Roll-over
• CPC Class Codes: B60R 2021/01272 Belt tensioners
• CPC Class Codes: B60R 2021/01327 Angular velocity or angular acceleration
• 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 21/13 Roll-over protection electrical circuits for triggering safety arrangements B60R21/01
• CPC Class Codes: B60R 22/46 Reels with means to tension the belt in an emergency by forced winding upelectrical circuits for triggering safety arrangements B60R21/01 ; tensioners using reels only guiding the belt during normal use, e.g. splitted reels B60R22/195

Abstract

An occupant restraint system includes a rollover prediction unit, a rollover detection unit, primary and secondary pre-tensioner units, and a control unit. The rollover prediction unit is configured to predict a rollover of the vehicle based on a state of the vehicle. The rollover detection unit is configured to detect a rollover of the vehicle based on the state of the vehicle. The primary and secondary pre-tensioner units are configured to apply a tension to a seat belt so as to restrain an occupant in a seat. An operation force of the secondary pre-tensioner unit is stronger than that of the primary pre-tensioner unit. The control unit is configured to activate the primary pre-tensioner unit based on a prediction by the rollover prediction unit that a rollover occurs and activate the secondary pre-tensioner unit based on a detection by the rollover detection unit that the rollover occurs.

Claims

1. An occupant restraint system comprising:

a seat belt configured to restrain an occupant in a seat of a vehicle;

a rollover prediction unit configured to predict a rollover of the vehicle based on a state of the vehicle;

a rollover detection unit configured to detect a rollover of the vehicle based on the state of the vehicle;

primary and secondary pre-tensioner units configured to apply a tension to the seat belt so as to restrain the occupant in the seat, an operation force of the secondary pre-tensioner unit being stronger than an operation force of the primary pre-tensioner unit; and

a control unit configured to activate the primary pre-tensioner unit based on a prediction by the rollover prediction unit that a rollover occurs and activate the secondary pre-tensioner unit based on a detection by the rollover detection unit that the rollover occurs.

2. An occupant restraint system as set forth in claim 1, wherein said rollover prediction unit comprises at least one of a steering angle sensor configured to detect an angle of a steering wheel, an acceleration sensor configured to detect an acceleration of the vehicle, a roll angle sensor configured to detect a roll angle of the vehicle, a brake sensor configured to detect a brake force, and a sensor for a curtain airbag.

3. An occupant restraint system as set forth in claim 1, wherein said rollover prediction unit predicts a rollover of the vehicle when a roll rate and a roll angle of the vehicle is in a predetermined second region above a predetermined first region in which a rollover of the vehicle is not predicted.

4. An occupant restraint system as set forth in claim 1, wherein said control unit is configured to detect an amount of slack in the seat belt and activate the primary pre-tensioner unit to retaract the seat belt when it is determined that the detected amount of slack is larger than a predetermined amount.

5. An occupant restraint system as set forth in claim 1, wherein said rollover detection unit comprises at least one of a steering angle sensor configured to detect an angle of a steering wheel, an acceleration sensor configured to detect an acceleration of the vehicle, a roll angle sensor configured to detect a roll angle of the vehicle, a brake sensor configured to detect a brake force, and a sensor for a curtain airbag.

6. An occupant restraint system as set forth in claim 3, wherein said predetermined second region has a lower second region and an upper second region above the lower second region, and wherein said rollover detection unit detects a rollover of the vehicle when a roll rate and a roll angle of the vehicle is in the upper second region and an acceleration of the vehicle is higher than a predetermined acceleration level.

7. An occupant restraint system as set forth in claim 3, wherein said rollover detection unit detects a rollover of the vehicle when a roll rate and a roll angle of the vehicle is in a predetermoined third region above the predetermined second region.

8. An occupant restraint system as set forth in claim 1, wherein said rollover prediction unit and said rollover detection unit are provided in one unit.

9. An occupant restraint system as set forth in claim 1, wherein said primary pre-tensioner unit is a reversible pre-tensioner unit.

10. An occupant restraint system as set forth in claim 1, wherein said primary pre-tensioner unit comprises a motor.

11. An occupant restraint system as set forth in claim 1, wherein said secondary pre-tensioner unit is a non-reversible pre-tensioner-unit.

12. An occupant restraint system as set forth in claim 1, wherein said secondary pre-tensioner unit comprises an explosive driver.

13. An occupant restraint system as set forth in claim 1, further comprising:

an occupant posture detection unit configured to detect a posture of the occupant and output an occupant posture signal,

wherein the control unit activates the primary pre-tensioner unit based on the rollover prediction signal and the occupant posture signal.

14. An occupant restraint system as set forth in claim 13, wherein said occupant posture detection unit is configured to detect a distance between a position of the occupant and a regular seating position and wherein the control unit is configured to activate the primary pre-tensioner unit for an operation time which increases as the distance increases.

15. An occupant restraint system as set forth in claim 13, wherein said occupant posture detection unit comprises a camera configured to capture an image of the occupant and an image recognition unit configured to determine the posture of the occupant based on the image captured by the camera.

16. An occupant restraint system as set forth in claim 13, wherein said occupant posture detection unit comprises an electrostatic capacity sensor configured to detect the posture of the occupant.

17. An occupant restraint system as set forth in claim 1, further comprising:

a collision sensor configured to detect a collision of the vehicle,

wherein the control unit activates the secondary pre-tensioner unit when the collision sensor detects a collision of the vehicle.

18. An occupant restraint system as set forth in claim 17, wherein said collision sensor comprises at least one of a side impact sensor, a frontal collision sensor and an acceleration sensor provided in a SRS unit.

19. An occupant restraint system as set forth in claim 1, further comprising:

another seat belt configured to restraint another occupant seated in another seat of the vehicle; and

tertiary and quaternary pre-tensioner units configured to apply a tension to said another seat belt so as to restrain said another occupant, wherein the control unit is configured to activate the tertiary pre-tensioner unit based on the rollover prediction signal and activate the quaternary pre-tensioner unit based on the rollover detection signal,and wherein an operation force of the tertiary pre-tensioner unit is stronger than an operation force of the quaternary pre-tensioner unit.

20. An occupant restraint system as set forth in claim 1, wherein an activation timing of the quaternary pre-tensioner unit differs from an activation timing of the secondary pre-tensioner unit.

21. An occupant restraint system as set forth in claim 1, wherein said secondary pre-tensioner unit comprises a motor.

22. An occupant restraint system comprising:

seat belt means for restraining an occupant in a seat of a vehicle;

rollover prediction means for predicting a rollover of the vehicle based on a state of the vehicle;

rollover detection means for detecting a rollover of the vehicle based on the state of the vehicle;

primary and secondary pre-tensioner means for applying a tension to the seat belt means so as to restrain the occupant in the seat, an operation force of the secondary pre-tensioner means being stronger than an operation force of the primary pre-tensioner means; and

control means for activating the primary pre-tensioner means based on a prediction by the rollover prediction means that a rollover occurs and activating the secondary pre-tensioner means based on a detection by the rollover detection means that the rollover occurs.

23. A method for restraining an occupant in a seat of a vehicle, the method comprising:

predicting a rollover of the vehicle based on a state of the vehicle;

detecting a rollover of the vehicle based on the state of the vehicle;

activating a primary pre-tensioner for applying a tension to a seat belt so as to restrain the occupant in the seat when a rollover is predicted;

activating a secondary pre-tensioner for applying a tension to the seat belt so as to restrain the occupant in the seat when a rollover is detected, an operation force of the secondary pre-tensioner being stronger than an operation force of the primary pre-tensioner.