US 11,987,231 B2
Method for ascertaining a characteristic variable of a clutch during generator operation
Ralf Mannsperger, Renchen (DE); and Timo Enders, Bensheim (DE)
Assigned to Schaeffler Technologies AG & Co. KG, Herzogenaurach (DE)
Appl. No. 17/292,752
Filed by Schaeffler Technologies AG & Co. KG, Herzogenaurach (DE)
PCT Filed Oct. 17, 2019, PCT No. PCT/DE2019/100906
§ 371(c)(1), (2) Date May 11, 2021,
PCT Pub. No. WO2020/103973, PCT Pub. Date May 28, 2020.
Claims priority of application No. 102018128961.8 (DE), filed on Nov. 19, 2018.
Prior Publication US 2021/0394742 A1, Dec. 23, 2021
Int. Cl. B60W 20/40 (2016.01); B60K 6/387 (2007.10); B60K 6/48 (2007.10); B60W 10/02 (2006.01); B60W 10/06 (2006.01); B60W 10/08 (2006.01)
CPC B60W 20/40 (2013.01) [B60K 6/387 (2013.01); B60K 6/48 (2013.01); B60W 10/02 (2013.01); B60W 10/06 (2013.01); B60W 10/08 (2013.01); B60W 2710/025 (2013.01); B60W 2710/027 (2013.01); B60W 2710/083 (2013.01)] 16 Claims
OG exemplary drawing
 
1. A method for ascertaining a characteristic variable of a clutch installed in a drive train of a vehicle for transmitting a transmission torque between a clutch input and a clutch output, wherein the drive train of the vehicle comprising:
a first electric motor is connected to the clutch input and to an internal combustion engine and may assume a generator operation when it is driven by the internal combustion engine,
a second electric motor is connected to the clutch output; the clutch input having a first rotational speed and the clutch output having a second rotational speed,
wherein, in response to ascertaining that a speed difference between the first rotational speed and the second rotational speed is less than a threshold value, the transmission torque during the generator operation is ascertained by activating the clutch to adopt a slipping state and setting a predefined rotational speed difference between the first and second rotational speed,
wherein, during the generator operation, the first electric motor causes a counter-torque opposing a drive torque from the internal combustion engine, wherein the transmission torque is ascertained to be equal to a torque difference between the drive torque and the counter-torque.
 
10. A method for ascertaining a characteristic variable of a clutch, the clutch comprising:
an input rotationally connected to a rotor of first electric motor and to an internal combustion engine and having a first rotational speed; and
an output rotationally connected to a rotor of a second electric motor which is driveably connected to vehicle wheels and having a second rotational speed;
the method comprising:
operating in a generator mode wherein the clutch is open and the first electric machine motor produces a counter-torque to resist a torque produced by the internal combustion engine; and
in response to determining a speed difference between the first rotational speed and the second rotational speed is less than a threshold value:
activating the clutch to adopt a slipping state;
maintaining the speed difference at a predetermined value; and calculating the characteristic variable based on a difference between the torque produced by the internal combustion engine and the counter-torque produced by the first electric motor.