Method for adapting a clutch characteristic curve when clutch hysteresis is present

• US 20090000901A1
• Filed: 06/20/2008
• Published: 01/01/2009
• Est. Priority Date: 06/25/2007
• Status: Active Grant

• Current Assignee: Schaeffler Technologies AG & Co.KG (INA-Holding Schaeffler GmbH & Co. KG)
• Original Assignee: LuK Lamellen und Kupplungsbau Beteiligungs KG
• Inventors: Reibold, Ekkehard
• Granted Patent: US 8,718,888 B2
• Time in Patent Office: Days
• US Class Current: 192/70.252
• CPC Class Codes: F16D 2500/30425 Estimation of the transmitted clutch torque, e.g. applying dynamic torque balance equation
• CPC Class Codes: F16D 2500/3067 Speed of the engine
• CPC Class Codes: F16D 2500/50236 Adaptations of the clutch characteristics, e.g. curve clutch capacity torque - clutch actuator displacement
• CPC Class Codes: F16D 2500/70673 Statistical calculations
• CPC Class Codes: F16D 48/06 Control by electric or electronic means, e.g. of fluid pressure

Abstract

A method for adapting a clutch characteristic curve, in particular one that exhibits hysteresis, where at least one characteristic value obtainable from the characteristic curve is compared to an appropriately measured characteristic value, and if the comparison shows that there is a deviation between the two characteristic values which is greater than a predetermined value, an adjustment is made to the clutch characteristic curve.

Claims

1. A method for adapting a clutch characteristic curve, exhibiting hysteresis, comprising the following steps:

comparing at least one characteristic value obtained from the characteristic curve to a corresponding measured characteristic value, and

adjusting the clutch characteristic curve if the comparison shows there is a deviation between the at least one obtained characteristic value and corresponding measured characteristic value greater than a predetermined value.

2. The method as recited in claim 1 wherein the characteristic value is a torque transmitted by the clutch.

3. The method as recited in claim 1 wherein the characteristic value is an engine rotation speed.

4. The method as recited in claim 1 wherein comparing the characteristic value includes determining the difference between the measured characteristic value and the characteristic value obtained from the characteristic curve.

5. The method as recited in claim 1 wherein the deviation is recoupled to the characteristic curve in a linear or non-linear manner.

6. The method as recited in claim 1 wherein the predetermined value is quantitatively half a hysteresis width of the clutch characteristic curve.

7. The method as recited in claim 1 wherein the predetermined value is half a mean hysteresis width of the clutch characteristic curve.

8. The method as recited in claim 1 wherein comparing the characteristic value includes determining an adaptation error, ascertaining whether the adaptation error is negative or positive, and incrementing and/or decrementing a counter which is different for the procedure “

engage clutch”

than for the procedure “

disengage clutch”

, depending on whether the adaptation error is positive or negative.

9. The method as recited in claim 1 further comprising enlarging a size of a dead zone if the counter for engaging the clutch is smaller than the negative of a certain threshold and the counter for disengaging the clutch is greater than the threshold, or reducing a size of the dead zone if the counter for engaging the clutch is greater than a certain threshold and the counter for disengaging the clutch is smaller than the negative of the threshold.