EXTERNAL AIRBAG DEPLOYMENT METHOD

• US 20150158446A1
• Filed: 05/09/2014
• Published: 06/11/2015
• Est. Priority Date: 12/11/2013
• Status: Active Grant

• Current Assignee: Hyundai Motor Company (Hyundai Motor Group)
• Original Assignee: Hyundai Motor Company (Hyundai Motor Group)
• Inventors: Lee, Han Sung, Kim, Yong Sun, Bae, Jin Ho
• Granted Patent: US 9,139,149 B2
• Time in Patent Office: Days
• US Class Current: 1/1
• CPC Class Codes: B60R 19/205 inflatable in the direction of an obstacle upon impending impact, e.g. using air bags
• CPC Class Codes: B60R 21/013 including means for detecting collisions, impending collisions or roll-over
• CPC Class Codes: B60R 21/0132 responsive to vehicle motion parameters , e.g. to vehicle longitudinal or transversal deceleration or speed value

Abstract

In an external airbag deployment method, a detection area located in front of a vehicle is set. A target object is selected from among objects detected in the detection area by comparing relative velocities, overlaps, and Time To External Airbag (TTE) values of the detected objects. It is determined whether the vehicle is stable or unstable by comparing a predicted yaw rate of the vehicle with a measured yaw rate. It is determined whether a relative velocity and an overlap of the target object, predicted at a time when the target object is assumed to collide with the vehicle, are greater than predetermined levels. The external airbag is deployed if it is determined that the vehicle is stable and the predicted relative velocity and overlap of the target object are greater than predetermined levels.

Claims

1. An external airbag deployment method, comprising:

a) setting a detection area located in front of a vehicle;

b) selecting a target object from among objects detected in the detection area by comparing relative velocities, overlaps, and Time To External Airbag (TTE) values of the detected objects, wherein a TTE is a remaining time until a collision with an airbag cushion occurs when an external airbag is assumed to be deployed;

c) determining whether the vehicle is stable or unstable by comparing a predicted yaw rate of the vehicle with a measured yaw rate;

d) determining whether the relative velocity and the overlap of the target object, predicted at a time when the target object is assumed to collide with the vehicle, are greater than predetermined levels, wherein the relative velocity and overlap are predicted in consideration of a system delay time; and

e) deploying the external airbag if it is determined that the vehicle is stable and the predicted relative velocity and overlap of the target object are greater than predetermined levels.

2. The external airbag deployment method of claim 1, wherein d) is configured to predict the relative velocity using the following equations:

predicted acceleration of target object=(mean of relative velocities for TT)/TT−

current acceleration of self vehicle 

 

1)

predicted relative velocity=current relative velocity−

(predicted acceleration of target object+current acceleration of self vehicle)×

Δ

T 

 

2)

Δ

T=TTC+system delay error 

 

3)

wherein TT denotes a predetermined time and TTC denotes a Time To Collision.

3. The external airbag deployment method of claim 1, wherein d) is configured to predict the overlap using the following equations:

predicted lateral relative velocity=mean of lateral relative velocities for TT 

 

1)

predicted overlap=(current overlap+predicted lateral relative velocity×

Δ

T)/width of self vehicle×

100 

 

2)

Δ

T=TTC+system delay error 

 

3)

wherein TT denotes a predetermined time and TTC denotes a Time To Collision.

4. The external airbag deployment method of claim 1, wherein b) is configured to select a detected object as the target object if the relative velocity of the detected object is greater than a first reference, the overlap of the detected object is greater than a second reference, and the TTE of the detected object is less than a third reference.

5. The external airbag deployment method of claim 4, wherein the predetermined levels at d) and e) are the first reference in case of the relative velocity and the second reference in case of the overlap, respectively.

6. The external airbag deployment method of claim 5, wherein the first reference is selected from a range between 40 km/h and 50 km/h.

7. The external airbag deployment method of claim 5, wherein the second reference is selected from a range between 10% and 30%.

8. The external airbag deployment method of claim 5, wherein the third reference is selected from a range between 70 ms and 90 ms.

9. The external airbag deployment method of claim 1, wherein:

d) comprises determining whether a collision probability based on a reciprocal of a Time To Collision (TTC) and a variation in collision probability are greater than predetermined levels, wherein the TTC is a remaining time until the target object collides with the vehicle at a time when the target object is assumed to collide with the vehicle, and

e) is configured to deploy the external airbag if the vehicle is stable, the predicted relative velocity and overlap of the target object are greater than the predetermined levels, and the collision probability and the variation in the collision probability are greater than the predetermined levels.

10. The external airbag deployment method of claim 1, wherein:

d) comprises calculating a required steering avoidance distance and a required braking avoidance distance based on the relative velocity of the target object, and comparing a distance to the target object with the required steering avoidance distance and the required braking avoidance distance, and

e) is configured to deploy the external airbag if the vehicle is stable, the predicted relative velocity and overlap of the target object are greater than the predetermined levels, and the distance to the target object is less than the required steering avoidance distance and the required braking avoidance distance.