Method and device for detecting motor vehicle tilt

• US 6,321,141 B1
• Filed: 09/24/1999
• Issued: 11/20/2001
• Est. Priority Date: 11/22/1997
• Status: Expired due to Fees

• Current Assignee: Robert Bosch GmbH
• Original Assignee: Robert Bosch GmbH
• Inventors: Leimbach, Klaus-Dieter
• Primary Examiner(s): Cuchlinski, Jr., William A.
• Assistant Examiner(s): MANCHO, RONNIE M
• Application Number:
  US09/355,199
• Time in Patent Office: 788 Days
• Field of Search: 701/1, 701/36, 701/45, 701/70-93, 180/282, 180/283, 180/284, 303/9.69, 318/586, 340/425.5, 434/61, 172/4.5, 172/2
• US Class Current: 701/1
• CPC Class Codes: B60G 2800/9124 Roll-over protection systems, e.g. for warning or control
• CPC Class Codes: B60R 16/0233 Vehicle tilting, overturning or roll over
• CPC Class Codes: B60T 2230/03 Overturn, rollover
• CPC Class Codes: B60T 8/172 Determining control parameters used in the regulation, e.g. by calculations involving measured or detected parameters B60T8/17551 takes precedence

Abstract

A method and a device are provided for detecting a tendency of a vehicle to tip about a vehicle axis oriented in the longitudinal direction of the vehicle. To this end, a variable is ascertained describing the dynamics of the vehicle linear motion. The detection strategy used for detecting the tendency of the vehicle to tip is selected from at least two detection strategies at least as a function of the variable describing the dynamics of the vehicle linear motion and/or the detection strategy used for detecting a tendency of the vehicle to tip is adapted, at least as a function of the variable describing the dynamics of the vehicle linear motion, to the dynamics of the vehicle linear motion existing at any one time.

Claims

1. A method for detecting a tendency of a vehicle to tip about a vehicle axis oriented in a longitudinal direction of the vehicle, comprising the steps of:

ascertaining a variable for describing dynamics of a vehicle linear motion; and

performing at least one of;

(A) selecting a detection strategy from at least two detection strategies, the at least two detection strategies being strategies for detecting the tendency of the vehicle to tip about the vehicle axis oriented in the longitudinal direction of the vehicle, the step of selecting being performed at least as a function of the variable for describing the dynamics of the vehicle linear motion; and

(B) adapting a detection strategy to the dynamics of the vehicle linear motion existing at any particular time, the step of adapting being performed at least as a function of the variable for describing the dynamics of the vehicle linear motion, the adapted detection strategy being a strategy for detecting the tendency of the vehicle to tip about the vehicle axis oriented in the longitudinal direction of the vehicle.

2. The method according to claim 1, wherein the method is used for stabilizing the vehicle, and further comprising the step of:

responding to the tendency of the vehicle to tip about the vehicle axis oriented in the longitudinal direction of the vehicle by stabilizing the vehicle by applying at least one of brake interventions at at least one wheel, engine interventions, and interventions at chassis actuators.

3. The method according to claim 2, wherein stabilizing the vehicle includes preventing the vehicle from overturning.

4. The method according to claim 1, further comprising the step of:

ascertaining, for at least one wheel, a variable for describing a rotary motion of a representative wheel;

wherein at least one the following conditions is satisfied;

(C) the step of ascertaining the variable for describing the dynamics of the vehicle linear motion is performed at least as a function of the variable for describing the rotary motion of the representative wheel; and

(D) the adapted detection strategy is at least a function of the variable for describing the rotary motion of the representative wheel.

5. The method according to claim 4, wherein the variable for describing the dynamics of the vehicle linear motion corresponds to at least one of a drive slip and a brake slip ascertained for the at least one wheel and prevailing at the at least one wheel.

6. The method according to claim 4, wherein the variable for describing the rotary motion of the representative wheel is a variable for describing a speed of the representative wheel.

7. The method according to claim 1, further comprising the step of:

comparing an absolute value of the variable for describing the dynamics of the vehicle linear motion with at least one corresponding threshold value;

wherein at least one of the following conditions is satisfied;

(C) the step of selecting the detection strategy is performed at least as a function of the comparing of the absolute value of the variable for describing the dynamics of the vehicle linear motion with the at least one corresponding threshold value; and

(D) the adapted detection strategy is at least a function of the comparing of the absolute value of the variable for describing the dynamics of the vehicle linear motion with the at least one corresponding threshold value.

8. The method according to claim 1, further comprising the step of:

ascertaining, for at least one wheel, a variable for describing wheel properties, and

wherein at least one of the at least two detection strategies is carried out at least as a function of the variable for describing the wheel properties.

9. The method according to claim 8, wherein the variable for describing the wheel properties for the at least one wheel is at least one of a diameter and a radius of a respective wheel.

10. The method according to claim 8, wherein the step of ascertaining the variable for describing wheel properties is performed at least as a function of at least one of a variable for describing a speed of a representative wheel, a variable for describing a vehicle speed, a variable for describing dynamics of a vehicle lateral motion and a variable for describing a vehicle geometry.

11. The method according to claim 8, further comprising the step of:

comparing an absolute value of the variable for describing the dynamics of the vehicle linear motion with at least one corresponding threshold value;

wherein at least one of the following conditions is satisfied;

(C) a first detection strategy of the at least two detection strategies is carried out when the absolute value of the variable for describing the dynamics of the vehicle linear motion is less than at least one corresponding threshold value, the first detection strategy being carried out at least as a function of the variable for describing the wheel properties, the variable for describing the wheel properties being ascertained for the at least one wheel in a prevailing time increment; and

(D) a second detection strategy of the at least two detection strategies is carried out when the absolute value of the variable for describing the dynamics of the vehicle linear motion is greater than the at least one corresponding threshold value, the second detection strategy being carried out at least as a function of the variable for describing the wheel properties, the variable for describing the wheel properties being ascertained for the at least one wheel in a previous time increment.

12. The method according to claim 8, at least one of the following:

(1) wherein in a first detection strategy of the at least two detection strategies, the vehicle has the tendency to tip about the vehicle axis oriented in the longitudinal direction of the vehicle when at least one of (C) a value of the variable for describing the wheel properties is greater than a first threshold value, (D) a value of the variable for describing the wheel properties is less than a second threshold value, (E) a difference between a value of the variable for describing the wheel properties and a comparison value is greater than a corresponding threshold value, (F) an absolute value of a variable for describing a time characteristic of the variable for describing the wheel properties is less than a corresponding threshold value, and (G) an absolute value of a variable for describing an angle of inclination of a wheel axle is greater than a corresponding threshold value, the variable for describing the wheel properties being determined for each wheel of a corresponding wheel axle, the variable for describing the angle of inclination of the corresponding wheel axle being determined as a function of the variables for describing the wheel properties for each wheel of the corresponding wheel axle, and

(2) wherein in a second detection strategy of the at least two detection strategies, the vehicle has the tendency to tip about the vehicle axis oriented in the longitudinal direction of the vehicle when an absolute value of a difference between a variable for describing a vehicle speed and a speed limiting value is less than a corresponding threshold value.

13. The method according to claim 12, wherein the speed limiting value is ascertained at least as a function of a variable for describing a height of a vehicle center of gravity, the variable for describing the height of the vehicle center of gravity being ascertained at least as a function of the variable for describing the wheel properties for the at least one wheel.

14. The method according to claim 1, further comprising the step of:

ascertaining a variable for describing dynamics of a vehicle lateral motion, and

wherein detecting the tendency of the vehicle to tip about the vehicle axis oriented in the longitudinal direction of the vehicle is carried out when an absolute value of the variable for describing the dynamics of the vehicle lateral motion is greater than a corresponding threshold.

15. The method according to claim 14, wherein the variable for describing the dynamics of the vehicle lateral motion includes at least one of a variable for describing a transverse acceleration and a variable for describing a yaw rate of the vehicle.

16. The method according to claim 1, wherein adapting the detection strategy to the dynamics of the vehicle linear motion existing at any particular time includes at least one of:

selecting at least one input variable of a plurality of input variables for carrying out the adapted detection strategy, the step of selecting the at least one input variable being at least a function of existing dynamics of the vehicle linear motion; and

implementing plausibility queries, the plausibility queries being altered at least as the function of the existing dynamics of the vehicle linear motion.

17. The method according to claim 16, wherein the plurality of input variables includes variables for describing wheel properties.

21. The method according to claim 12, wherein the variable for describing the wheel properties describes wheel performance.

18. A device for detecting a tendency of a vehicle to tip about a vehicle axis oriented in a longitudinal direction of the vehicle, comprising:

means for ascertaining a variable for describing dynamics of a vehicle linear motion; and

at least one of (A) means for selecting a detection strategy from at least two detection strategies, the at least two detection strategies being strategies for detecting the tendency of the vehicle to tip about the vehicle axis oriented in the longitudinal direction of the vehicle, the selecting being at least a function of the variable for describing the dynamics of the vehicle linear motion and (B) means for adapting a detection strategy to the dynamics of the vehicle linear motion existing at any particular time, the adapting being at least a function of the variable for describing the dynamics of the vehicle linear motion, the adapted detection strategy being a strategy for detecting the tendency of the vehicle to tip about the vehicle axis oriented in the longitudinal direction of the vehicle.

19. The device according to claim 18, wherein the device is used in a device for stabilizing the vehicle and wherein, in response to the tendency of the vehicle to tip about the vehicle axis oriented in the longitudinal direction of the vehicle, at least one of brake interventions at at least one wheel, engine interventions, and interventions at chassis actuators are implemented.

20. The device according to claim 19, wherein the device for stabilizing the vehicle includes a device for preventing the vehicle from overturning.