Process and device for stabilizing a vehicle on the basis of a determined torsional value

• US 6,324,447 B1
• Filed: 06/02/2000
• Issued: 11/27/2001
• Est. Priority Date: 06/23/1998
• Status: Expired due to Fees

• Current Assignee: Robert Bosch GmbH
• Original Assignee: Robert Bosch GmbH
• Inventors: Faye, Ian, Schramm, Herbert
• Primary Examiner(s): Cuchlinski, Jr., William A.
• Assistant Examiner(s): ARTHUR JEANGLAUDE, GERTRUDE
• Application Number:
  US09/486,347
• Time in Patent Office: 543 Days
• Field of Search: 701/1, 701/8, 701/38, 701/72, 701/93, 303/141, 303/143, 303/154, 303/171, 303/173, 280/6.159
• US Class Current: 701/1
• CPC Class Codes: B60G 2400/63 Location of the center of gravity
• CPC Class Codes: B60G 2800/0124 Roll-over conditions
• CPC Class Codes: B60G 2800/215 by applying a braking action on each wheel individually
• CPC Class Codes: B60G 2800/702 Improving accuracy of a sensor signal
• CPC Class Codes: B60G 2800/922 EBV - Electronic brake force distribution
• 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 method for stabilizing a vehicle to avoid at least one of a vehicle rolling over about a vehicle axis oriented in the longitudinal direction of the vehicle and the vehicle sliding in the transverse direction. The method determines at least one of a torsion variable that corresponds to how the vehicle behaves in reaction to a force acting on the vehicle about the vehicle axis oriented in the vehicle'"'"'s longitudinal direction, and a load-shift variable that corresponds to how the vehicle load behaves in reaction to a force acting upon the vehicle. The method determines a vehicle speed and also determines at least one threshold value for the vehicle speed based on the torsion variable and the load-shift variable. The vehicle speed and the at least one threshold value are then compared, and interventions (or measures) are taken to stabilize the vehicle based on the comparison.

Claims

1. A method for stabilizing a vehicle, the method comprising the steps of:

determining at least one of a torsion variable, which corresponds to a vehicle behavior that occurs in reaction to at least one of a force and a transverse force operating on the vehicle with respect to a vehicle axis oriented in a longitudinal direction of the vehicle, and a load-shift variable, which corresponds to a load behavior of a load associated with the vehicle that occurs in reaction to the at least one of the force and the transverse force operating on the vehicle, wherein the vehicle behavior corresponds to the vehicle being at least one of turned, twisted and displaced about the vehicle axis and the load behavior corresponds to the load being at least one of moved, shifted and displaced;

determining a speed variable that corresponds to a vehicle speed;

determining at least one threshold value based on at least one of the torsion variable and the load-shift variable;

comparing the speed variable and the at least one threshold value and providing a comparison result; and

based on the comparison result, intervening in a vehicle operation to avoid at least one of overturning the vehicle about the vehicle axis and sliding the vehicle in a transverse direction.

2. The method of claim 1, wherein the torsion variable is determined based on a mass variable corresponding to a vehicle mass.

3. The method of claim 1, further comprising the step of determining a mass variable based on a motive force acting on the vehicle and at least one wheel speed, wherein the at least one threshold value for the vehicle speed is determined based on the mass variable.

4. The method of claim 1, further comprising at least one of the steps of:

(a) determining a mass variable; and

(b) determining a volume of the load based on one of the mass variable and a variable corresponding to a form of a vehicle load device, wherein if the load is a fluid load, then the volume is determined during one of a loading and unloading of the vehicle load device;

wherein the load-shift variable is determined based on at least one of the mass variable and the volume.

5. The method of claim 1, wherein in the step of intervening, if the speed variable is greater than the at least one threshold value, then the vehicle speed is reduced by intervening in at least one of a retarder operation, an engine operation and a braking operation so that the speed variable is reduced below the at lest one threshold value.

6. The method of claim 1, further comprising the step of selecting a smaller one of a first threshold value and a second threshold value, which are the at least one threshold value, for comparing to the speed variable, wherein at least one of the first threshold value and the second threshold value corresponds to one of a vehicle overturning risk and a vehicle sliding risk.

7. The method of claim 6, further comprising one of the steps of:

(a) determining at least one friction variable corresponding to friction conditions between at least one vehicle tire and a road surface, wherein the at least one threshold value is determined based on the at least one friction variable; and

(b) determining a first friction variable corresponding to a current friction value and a second friction variable corresponding to a difference in frictional values of each side of the vehicle, wherein the at least one threshold value is determined based on at least one of the first friction variable and the second friction variable.

8. The method of claim 6, further comprising at least one of the steps of:

determining a first height variable, which corresponds to a distance between a center of gravity of the vehicle and a road surface, based on at least one wheel speed variable; and

determining a second height variable, which corresponds to a distance between the road surface and the vehicle axis, based on a mass variable corresponding to a vehicle mass;

wherein the at least one threshold value is determined based on at least one of the first height variable and the second height variable.

9. The method of claim 1, further comprising one of the following steps of:

determining a path variable corresponding to a radius of a path being driven by the vehicle; and

determining the path variable based on at least one of the speed variable and a steering angle variable corresponding to a steering angle of the vehicle;

wherein the at least one threshold value is determined based on the path variable.

10. A device for stabilizing a vehicle, comprising:

means for determining at least one of a torsion variable, which corresponds to a vehicle behavior that occurs in reaction to at least one of a force and a transverse force operating on the vehicle with respect to a vehicle axis oriented in a longitudinal direction of the vehicle, and a load-shift variable, which corresponds to a load behavior of a load associated with the vehicle that occurs in reaction to the at least one of the force and the transverse force operating on the vehicle, wherein the vehicle behavior corresponds to the vehicle being at least one of turned, twisted and displaced about the vehicle axis and the load behavior corresponds to the load being at least one of moved, shifted and displaced;

means for determining a speed variable that corresponds to a vehicle speed;

means for determining at least one threshold value based on at least one of the torsion variable and the load-shift variable;

means for comparing the speed variable and the at least one threshold value and providing a comparison result; and

means for intervening in a vehicle operation, based on the comparison result, to avoid at least one of overturning the vehicle about the vehicle axis and sliding the vehicle in a transverse direction.