Method for operating a clutch of a motor vehicle, and motor vehicle

Patent metadata

Field	Value
Publication number	US-11174906-B2
Application number	US-201716321568-A
Country	US
Kind code	B2
Filing date	Jul 26, 2017
Priority date	Aug 4, 2016
Publication date	Nov 16, 2021
Grant date	Nov 16, 2021

Abstract

A method for operating a clutch of a drive train of a vehicle wherein the clutch, a drive motor primary axis having first wheels that can be driven by the drive motor as first axis and a second axis having second wheels are driven by the drive motor via the clutch as second axis, with the clutch being adjusted between a closed position, wherein a first coupling torque of the clutch is set, and at least one second position differing from the closed position, wherein a second coupling torque of the clutch that is lower than the first coupling torque is set: determining at least one coefficient of friction of a roadway the vehicle is located on; and as a factor of the determined coefficient of friction: adjusting a basic torque of the clutch, with the clutch being prestressed in the second position by the basic torque.

First claim

The invention claimed is:

1. A method for operating a first clutch at a first separation point of a drive train of a vehicle, and a second clutch at a second separation point of the drive train of the vehicle, the vehicle having the first clutch, the second clutch, a drive motor, a primary axis
having first wheels drivable by the drive motor as a first axis, and a secondary axis having second wheels drivable by the drive motor via the first clutch and the second clutch as a second axis, the method comprising:
adjusting the first clutch between a closed position, wherein a first coupling torque of the first clutch is set, and at least a second position differing from the closed position, wherein a second coupling torque of the first clutch that is lower than the first coupling torque is set;
determining at least one coefficient of friction of a roadway the vehicle is located on; and
as a factor of the determined coefficient of friction, adjusting the second coupling torque of the first clutch, the first clutch being prestressed in the second position by the second coupling torque;
wherein, when the first clutch is adjusted to the closed position, the second clutch is adjusted to a coupled position; and
when the first clutch is adjusted to the second position, the second clutch is adjusted to a decoupled position.

2. The method according to claim 1 , wherein the second coupling torque is adjusted as a factor of a steering angle of the vehicle.

3. The method according to claim 1 , wherein a speed of at least one of the wheels is measured, with the coefficient of friction being determined as a factor of the measured speed.

4. The method according to claim 1 , wherein the coefficient of friction is determined as a factor of a steering angle of the vehicle.

5. The method according to claim 1 , wherein at least one acceleration affecting the vehicle is measured, with the coefficient of friction being determined as a factor of the measured acceleration.

6. The method according to claim 1 , wherein the coefficient of friction is determined as a factor of a yaw rate of the vehicle.

7. The method according to claim 1 , wherein by an electronic computing device of the vehicle, based on at least one computational model, an expected behavior of the vehicle is calculated, with the coefficient of friction being determined as a factor of calculated behavior.

8. The method according to claim 1 , wherein as the clutch a frictionally engaged clutch is being used.

9. The method according to claim 8 , wherein the frictionally engaged clutch is a multi-plate clutch.

Assignees

• Audi Ag

Inventors

• Baer Michael
• Arndt Martin
• Graf Christian
• Wein Michael
• Baur Marc
• Lehner Stefan
• Huefner Stefan

Classifications

• B60K23/02 Primary

  for main transmission clutches · CPC title

• F16D2500/3109

  Vehicle acceleration · CPC title

• B60K17/348

  having differential means for driving one set of wheels, e.g. the front, at one speed and the other set, e.g. the rear, at a different speed (B60K17/346 takes precedence) · CPC title

• F16D13/52

  Clutches with multiple lamellae {; Clutches in which three or more axially moveable members are fixed alternately to the shafts to be coupled and are pressed from one side towards an axially-located member (F16D13/385 takes precedence)} · CPC title

• F16D2500/3102

  Vehicle direction of travel, i.e. forward/reverse · CPC title