Method for rollover detection for automotive vehicles with safety-related devices

• US 20030023359A1
• Filed: 05/22/2001
• Published: 01/30/2003
• Est. Priority Date: 05/22/2000
• Status: Active Grant

• Current Assignee: Temic Telefunken Microelectronic GmbH (Continental AG)
• Original Assignee: Temic Telefunken Microelectronic GmbH (Continental AG)
• Inventors: Steiner, Peter, Steurer, Helmut, Kueblbeck, Hermann, Rottenkolber, Ernst, Weidel, Peter
• Granted Patent: US 6,618,656 B2
• Time in Patent Office: Days
• US Class Current: 701/45
• CPC Class Codes: B60G 2800/9124 Roll-over protection systems, e.g. for warning or control
• CPC Class Codes: B60R 2021/0018 Roll-over
• CPC Class Codes: B60R 2021/01306 monitoring vehicle inclination
• CPC Class Codes: B60R 2021/01325 Vertical acceleration
• CPC Class Codes: B60R 2021/01327 Angular velocity or angular acceleration
• 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

Method for rollover detection for automotive vehicles with safety-related devices, such as roll bars, (side) airbags and seat-belt tensioners.

In a known method according to DE 196 09 717 A1, in which an angular rate sensor measures the angular velocity in each case around the vertical axis (yaw axis), the longitudinal axis and the transverse axis (pitch axis) of the vehicle, a rollover is detected when at least one of the measured angular velocities exceeds a defined threshold value (limit value). This publication further proposes calculating the rotational energy of the vehicle from the angular velocities, and indicating an impending rollover when the rotational energy exceeds a defined threshold. However, the disadvantage of this method is that false decisions cannot be excluded, when for example the vehicle is traveling over steep terrain or is subject to slow rolling motions while traveling around curves, especially into steep curves.

According to the invention, starting from the initial position angle indicating the initial position of the vehicle, the integrated angular rate signal—as angle of rotation—is added so that the value proportional to the momentary inclination angle (in relation to the horizontal plane) can be compared to a trigger threshold which is a function of the angular rate. A safety-related device is triggered if this trigger threshold is exceeded by the cumulative value.

Claims

1. Process for rollover detection for automotive vehicles with safety-related devices wherein, by means of an angular rate signal (ω

_x) generated by a gyrosensor (1) in respect of a rotation around the longitudinal axis (X-axis) of the vehicle and by means of an initial position signal (α

_D) generated by a sensor (2) stating the initial position of the transverse axis of the vehicle, the following process steps are performed;

a) calculation of the current inclination angle (α

_{curr, calc}) according to

∫

ω

dt+α

_start=α

_curr,calc, with α

_start=α

₀ 

 

(1)

b) generating a trigger threshold (S(ω

)) according to

S(ω

)=α

_tip−

k|ω

|, 

 

(2)

in which α

_tip corresponds to the static tipping angle of the vehicle and k is a settable vehicle-specific constant which is also a function of the vehicle condition and/or the crash sequence,

c) comparison of the value of the absolute amount of the calculated angle of inclination (α

_curr,calc) with the value of the trigger threshold (S(ω

), and

d) generation of a trigger signal for at least one safety-related device when the trigger threshold (S(ω

)) is exceeded according to

|α

_curr,cals|>

S(ω

).

2. Process according to claim 1 wherein, as well as the detection of the angle of rotation (ω

_x) and the initial position (α

₀) of the vehicle, additional dynamic motion variables (a_y, a_z, α

_incl) of the vehicle are detected and the following additional process steps are performed;

e) evaluation of the values of the additional dynamic motion vanables (a_y, a_z, α

_incl for self-consistency,

f) determination of the current inclination angle (α

_curr) from the dynamic motion variables (a_y, a_z, α

_incl) if the dynamic motion variables (a_y, a_z, α

_incl) are evaluated as self-consistent,

f1) resetting the calculated current inclination angle (α

_curr,calc) to the value of this current inclination angle (α

_curr),

f2) resetting the integral ∫

ω

_xdt to the value zero, and

f3) then calculating the current inclination angle (α

_curr,calc) according to;

∫

ω

dt+α

_start=α

_curr,calc, with α

_start=α

_curr 

 

(1)

g) Returning the calculated current inclination angle (α

_curr,calc) to an assessed value (α

_ass) of the current inclination angle (α

_curr);

when the values of the dynamic motion variables (a_y, a_z, α

_incl) are evaluated as not being self-consistent and then calculating the current inclination angle (α

_curr,calc) according to;

∫

ω

dt+α

_start=α

_curr,calc with.α

_start=α

_ass 

 

(1′

′

)

3. Process according to claim 2 wherein the value zero or the value of the last of the inclination angles determined from the dynamic motion variables (a_y, a_z, α

_incl) which was evaluated as self-consistent is used as the assessed value (α

_ass).

4. Process according to claim 3 wherein the calculated current inclination angle (α

_curr,calc) is returned in stages to the assessed value (α

_ass) in successive time segments.

5. Process according to claim 4 wherein at least the vertical acceleration (a_z) and lateral acceleration (a_y) detected by acceleration sensors (3) and the inclination angle of the vehicle detected by an inclination sensor (2) are used as dynamic motion variables (a_y, a_z, α

_incl).

6. Process according to claim 5 wherein the signal of the inclination sensor (2) is defined as the value of the current inclination angle (α

_curr) in accordance with process step f).

7. Process according to claim 3 wherein the calculated current inclination angle (α

_curr,calc) is continuously returned to the assessed value (α

_ass) during a defined time segment.

8. Process according to claim 7 wherein at least the vertical acceleration (a_z) and lateral acceleration (a_y) detected by acceleration sensors (3) and the inclination angle of the vehicle detected by an inclination sensor (2) are used as dynamic motion variables (a_y, a_z, α

_inc).

9. Process according to claim 8 wherein the signal of the inclination sensor (2) is defined as the value of the current inclination angle (α

_curr) in accordance with process step f).

10. Process according to claim 2 wherein at least the vertical acceleration (α

_z) and lateral acceleration (a_y) detected by acceleration sensors (3) and the inclination angle of the vehicle detected by an inclination sensor (2) are used as dynamic motion variables (a_y, a_z, α

_incl).

11. Process according to claim 10 wherein the signal of the inclination sensor (2) is defined as the value of the current inclination angle (α

_curr) in accordance with process step f).