Antilock braking system based roll over prevention

• US 20030225499A1
• Filed: 05/30/2002
• Published: 12/04/2003
• Est. Priority Date: 05/30/2002
• Status: Active Grant

• Current Assignee: Bendix Commercial Vehicle Systems LLC (Estate of Heinz Hermann Thiele)
• Original Assignee: Bendix Commercial Vehicle Systems LLC (Estate of Heinz Hermann Thiele)
• Inventors: Holler, Gusztav
• Granted Patent: US 6,741,922 B2
• Time in Patent Office: Days
• US Class Current: 701/71
• CPC Class Codes: B60G 2300/04 Trailers
• CPC Class Codes: B60G 2400/104 lateral or transversal with regard to vehicle
• CPC Class Codes: B60G 2800/012 Rolling condition
• CPC Class Codes: B60G 2800/0124 Roll-over conditions
• CPC Class Codes: B60G 2800/922 EBV - Electronic brake force distribution
• 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: B60T 2230/03 Overturn, rollover
• CPC Class Codes: B60T 8/17554 specially adapted for enhancing stability around the vehicles longitudinal axle, i.e. roll-over prevention road vehicle drive control systems for roll-over prevention otherwise than by controlling a particular sub-unit B60W30/04

Abstract

A rollover prevention system for a vehicle includes an antilock braking system and a plurality of wheel-end modulator valves associated with respective wheels. The antilock braking system includes an electronic control unit and a lateral acceleration estimator for determining a lateral acceleration of the vehicle. The wheel-end modulator valves cause respective braking pressures to be applied at the respective wheels as a function of the lateral acceleration of the vehicle and a level of frictional contact between the wheels and a driving surface.

Claims

1. A rollover prevention system for a vehicle, comprising:

an antilock braking system including an electronic control unit and a plurality of wheel-end modulator valves associated with respective wheels; and

a lateral acceleration estimator for determining a lateral acceleration of the vehicle, the wheel-end modulator valves causing respective braking pressures to be applied at the respective wheels as a function of the lateral acceleration of the vehicle and a level of frictional contact between the wheels and a driving surface.

2. The rollover prevention system for a vehicle as set forth in claim 1, wherein the wheel-end modulator valves cause a pulsed braking pressure to be applied to the wheels having less than a predetermined level of frictional contact with the driving surface if the lateral acceleration of the vehicle is greater than a predetermined entry level.

3. The rollover prevention system for a vehicle as set forth in claim 1, wherein:

the wheels are at opposed ends of an axle; and

the electronic control unit determines the lateral acceleration as a function of respective velocities of the wheels and a distance between the wheels along the axle.

4. The rollover prevention system for a vehicle as set forth in claim 3, wherein if the lateral acceleration exceeds a predetermined entry level:

one of the opposed wheels is associated with an inner turning curvature of the vehicle and another one of the opposed wheels is associated with an outer turning curvature of the vehicle; and

one of the wheel-end modulator valves applies a pulsed braking pressure to the inner wheel.

5. The rollover prevention system for a vehicle as set forth in claim 4, wherein if the electronic control unit determines the inner wheel locks in response to the pulsed braking pressure, the electronic control unit causes the service brake chambers to apply braking pressures to the respective wheels for slowing a rotational rate of the wheels.

6. The rollover prevention system for a vehicle as set forth in claim 5, wherein the electronic control unit causes the service brake chambers to apply the braking pressures to the respective wheels until the lateral acceleration of the vehicle is less than a predetermined exit level.

7. An apparatus for predicting a rollover event of a vehicle including an axle, having a plurality of opposed wheels, and a plurality of modulator valves associated with respective ones of the wheels and respective wheel brake chambers, the apparatus comprising:

means for determining a lateral acceleration of the vehicle; and

means for determining if any of the wheels is not in contact with a driving surface, the wheel-end modulator valves causing respective braking pressures to be applied at the wheel brake chambers if any of the wheels is not in frictional contact with the driving surface and the lateral acceleration of the vehicle exceeds a predetermined entry level.

8. The apparatus for predicting a rollover event of a vehicle as set forth in claim 7, wherein the lateral acceleration “

a”

of the vehicle is determined according to;

a=((V₁+V₂)/2)2/(t/(V₂/V₁−

1));

where;

V₁=a speed of one of the opposed wheels;

V₂=a speed of another of the opposed wheels; and

t=a length of the axle between the opposed wheels.

9. The apparatus for predicting a rollover event of a vehicle as set forth in claim 7, wherein:

the means for determining if any of the wheels is not in frictional contact with the driving surface sets an alert mode if the estimated lateral acceleration exceeds a predetermined alert mode entry level; and

during the alert mode, the means for determining if any of the wheels is not in frictional contact with the driving surface causes a pulsed braking test pressure to be applied to the inner wheels via the respective modulator valves.

10. The apparatus for predicting a rollover event of a vehicle as set forth in claim 9, wherein, during the alert mode, the means for determining if any of the wheels is not in frictional contact with the driving surface causes a constant braking test pressure to be applied to the outer wheels via the respective modulator valves.

11. The apparatus for predicting a rollover event of a vehicle as set forth in claim 10, wherein the means for determining if any of the wheels is not in frictional contact with the driving surface terminates the alert mode if the lateral acceleration becomes less than an alert mode exit level.

12. The apparatus for predicting a rollover event of a vehicle as set forth in claim 9, wherein the means for determining if any of the wheels is not in frictional contact with the driving surface causes automatic braking pressures to be applied to all of the wheels via the respective modulator valves for decelerating the vehicle as a function of whether the pulsed braking test pressure causes the inner wheel to lock.

13. The apparatus for predicting a rollover event of a vehicle as set forth in claim 12, wherein the means for determining if any of the wheels is not in frictional contact with the driving surface causes the automatic braking pressures to stop being applied to all of the wheels when the lateral acceleration is less than an automatic intervention mode exit level.

14. The apparatus for predicting a rollover event of a vehicle as set forth in claim 7, wherein the vehicle is at least one of a heavy duty truck, tractor, trailer, or tractor-trailer combination.

15. A method for preventing a rollover of a vehicle including an antilock braking system, the method comprising:

calculating a lateral acceleration of the vehicle;

if the lateral acceleration exceeds a predetermined alert mode entry level, setting an electronic control unit to be in an alert mode;

during the alert mode, applying a test pressure to a plurality of wheels on the vehicle;

monitoring respective velocities of the wheels for determining if any of the wheels is in a lockup condition; and

if the lockup condition is detected for any of the wheels, applying a braking pressure to all of the wheels.

16. The method for preventing a rollover as set forth in claim 15, wherein the calculating includes:

monitoring velocities of opposed wheels along an axle of the vehicle length.

17. The method for preventing a rollover as set forth in claim 16, wherein the applying includes:

pulsing a braking pressure to one of the opposed wheels and applying a constant braking pressure to the other of the opposed wheels.

18. The method for preventing a rollover as set forth in claim 15, further including:

if the lateral acceleration drops below an alert mode exit level, setting the electronic control unit to not be in the alert mode.

19. An antilock braking system, comprising:

an electronic control unit; and

a lateral acceleration estimator for determining a lateral acceleration of the vehicle, the electronic control unit causing respective braking pressures to be applied to a plurality of wheels of a vehicle as a function of the lateral acceleration of the vehicle and a level of frictional contact between the wheels and a driving surface.

20. The antilock braking system as set forth in claim 19, wherein the further including:

a plurality of wheel-end modulator valves communicating with the electronic control unit for causing the braking pressures to be applied at the respective wheels.

21. The antilock braking system as set forth in claim 19, wherein if the electronic control unit determines one of the wheels locks in response to a pulsed braking pressure, the electronic control unit causes braking pressures to be applied to the respective wheels for slowing a rotational rate of the wheels until the lateral acceleration estimator determines the lateral acceleration of the vehicle is less than a predetermined level.