METHOD FOR OPERATING A DRIVE TRAIN

• US 20120109476A1
• Filed: 07/02/2010
• Published: 05/03/2012
• Est. Priority Date: 07/09/2009
• Status: Active Grant

• Current Assignee: ZF Friedrichshafen AG (Zeppelin - Stiftung der Stadt Friedrichshafen)
• Original Assignee: ZF Friedrichshafen AG (Zeppelin - Stiftung der Stadt Friedrichshafen)
• Inventors: Wiencek, Norbert
• Granted Patent: US 9,073,550 B2
• Time in Patent Office: Days
• US Class Current: 701/60
• CPC Class Codes: B60W 10/02 including control of driveline clutches
• CPC Class Codes: B60W 2510/1015 Input shaft speed, e.g. turbine speed
• CPC Class Codes: B60W 2710/022 Clutch actuator position
• CPC Class Codes: B60W 30/18027 Drive off, accelerating from standstill
• CPC Class Codes: B60W 30/18072 Coasting
• CPC Class Codes: F16D 2500/30816 Speed of the input shaft
• CPC Class Codes: F16D 2500/50825 Hill climbing or descending
• CPC Class Codes: F16D 2500/5085 Coasting
• CPC Class Codes: F16D 2500/7041 Position
• CPC Class Codes: F16D 48/06 Control by electric or electronic means, e.g. of fluid pressure
• CPC Class Codes: Y02T 10/60 Other road transportation technologies with climate change mitigation effect

Abstract

A method of operating a drive-train which comprises a drive aggregate, a transmission and a starting clutch connected between the drive aggregate and the transmission such that during rolling and coasting, in a thrust operation, the drive-train is operated in such manner that a target value for the position of the clutch is determined as a function of a transmission input speed. The target value for the position of the clutch is compared with a corresponding actual value and, on the basis of the deviation between the target and actual values, a control parameter is generated for adjusting the clutch. The target value for the position of the clutch, during rolling and coasting, is determined in such manner that for a defined value of the transmission input speed, a target value is determined for the position of the clutch when rolling which is different from that determined when coasting.

Claims

1-12. -12. (canceled)

13. A method of operating a drive-train in which the drive-train comprises a drive aggregate, a transmission and a starting clutch connected between the drive aggregate and the transmission, the method comprising the steps of:

operating the drive-train during rolling in a thrust operation and during coasting in a thrust operation and determining a target value for the position of the starting clutch as a function of a transmission input speed;

comparing the target value for the position of the starting clutch with a corresponding actual value of the position of the starting clutch;

generating a control parameter, for adjusting the starting clutch, in a regulator and on a basis of a deviation between the target value for the position of the starting clutch and the actual value of the position of the starting clutch; and

determining the target value for the position of the starting clutch, during rolling and during coasting, in such manner that for a given value of the transmission input speed, the target value determined for the position of the starting clutch during rolling is different from the target value determined for the position of the starting clutch during coasting.

14. The method according to claim 13, further comprising the step of determining the respective target values for the position of the starting clutch for rolling and for coasting on a basis of one of separate characteristic curves and performance curves.

15. The method according to claim 13, further comprising the step of, for rolling, for each gear there is at least one characteristic curve on a basis of which, as a function of the transmission input speed, a target value is determined during rolling for the position of the starting clutch which is to be closed farther.

16. The method according to claim 13, further comprising the step of, for coasting, for each gear there is at least one characteristic curve on the basis of which, as a function of the transmission input speed, a target value is determined during coasting for the position of the starting clutch which is to be opened farther.

17. The method according to claim 13, further comprising the step of determining the transmission input speed by measurement means and using the measured transmission input speed an input magnitude for determining the target value for the position of the starting clutch for rolling and for coasting.

18. The method according to claim 13, further comprising the step of calculating the transmission input speed from a measured transmission output speed and the calculated transmission input speed as an input magnitude for determining the target value for the position of the starting clutch for rolling and for coasting.

19. A method of operating a drive-train, the drive-train comprising a drive aggregate, a transmission and a starting clutch connected between the drive aggregate and the transmission, the method comprising the steps of:

operating the drive-train during rolling in a thrust operation and during coasting in a thrust operation and determining a target value for a position of the starting clutch as a function of a transmission input speed;

comparing the target value for the position of the starting clutch with a corresponding actual value of the position of the starting clutch;

generating a control parameter, for adjusting the starting clutch, in a regulator and on a basis of a deviation between the target value for the position of the starting clutch and the actual value of the position of the starting clutch; and

determining the control parameter for adjusting the starting clutch on a basis of a deviation between the target value for the position of the starting clutch and the actual value of the position of the starting clutch, and additionally on the basis of the absolute actual value of the position of the starting clutch.

20. The method according to claim 19, further comprising the step of generating an adjustment speed of the starting clutch as the control parameter for adjusting the starting clutch.

21. The method according to claim 20, further comprising the step of, if the absolute actual value of the position of the starting clutch is indicative of a fully disengaged starting clutch, then for the same relative deviation between the target value for the position of the starting clutch and the actual value of the position of the starting clutch, determining a lower adjustment speed for coasting and thus for a starting clutch which is to be disengaged further, than for rolling and thus for a starting clutch which is to be engaged further.

22. The method according to claim 20, further comprising the step of, if the absolute actual value of the position of the starting clutch is indicative of a fully disengaged starting clutch, then for the same relative deviation between the target value for the position of the starting clutch and the actual value of the position of the starting clutch, determining a lower adjustment speed is determined for rolling and thus for the starting clutch which is to be engaged further than for coasting and thus for a starting clutch which is to be disengaged further.