Zf Friedrichshafen Ag

Falko Platzer

Thomas Lemp

Felix Bühle

Peter Schiele

Michael Sohler

Klaus Steinhauser

Werner Wolfgang

Christoph Hess

Alexander Jungaberle

A method for operating a drive train of a motor vehicle may include, for a starting process of an internal combustion engine, transferring the separating clutch from a disengaged condition into an engaged condition or a slip state such that the electric machine accelerates the internal combustion engine to a starting speed. The method may further include actuating a torque-transmitting element between the electric machine and the output shaft to enter a slip state. The method may also include increasing the torque of the electric machine to reliably reach and hold the slip state of the torque-transmitting element. Additionally, the method may include operating the electric machine as a generator or as a motor depending on an expected load direction of the drive train during the starting process to reliably reach and hold the torque-transmitting element in the slip state.

Method and control unit for operating a motor vehicle drive train

A method for operating a drive train of a motor vehicle, the drive train having at least one transmission () for carrying out different transmission gear ratios between an input shaft () and an output shaft () of the transmission () by selectively engaging hydraulically actuatable shift elements of the transmission (G), the drive train further having an electric machine as a drive source (), and a hydraulically actuatable or bridgeable starting component () in the power path between the drive source () and the output shaft (). The method includes performing a starting process of the motor vehicle driven solely by the drive source () with an engaged or bridged starting component (). The method further includes limiting a drive source torque () during the starting process to a maximum value dependent on a current system pressure () of a hydraulic system of the transmission ().

Method for operating a drive train of a motor vehicle, and drive train module of a motor vehicle of this type

A method for operating a drivetrain of a motor vehicle, includes, when the motor vehicle is at a standstill and upon demand for a drive torque of the motor vehicle, increasing power () supplied to a separate electric pump drive () such that a pressure chamber whose pressurization effects a complete closure or lock-up of a launch element () is fast charged with hydraulic pressure from a pump (). The method also includes performing a launch process of the motor vehicle with the drive source () and with a closed or locked-up launch element () and reducing the power () supplied to the separate electric pump drive () after fast charging the pressure chamber. A related drive train module is also provided.

Method for operating a drivetrain of a motor vehicle, and drivetrain module of motor vehicle of said type

A method for operating a drive train of a motor vehicle includes performing a startup operation of the motor vehicle or a stopping operation of the motor vehicle. A starting component () is engaged or bridged during the startup operation or the stopping operation of the motor vehicle. The startup operation is driven by a drive source (). The method also includes comparing an actual value of an output shaft () based variable with a target value of the output shaft () based variable during the startup operation or the stopping operation and, on reaching or exceeding a specific deviation of the actual value from the target value, moving the starting component () into a slipping state. The starting component () transmits torque in the slipping state. A related drive train module for a motor vehicle is also provided.

Method for operating a drive train of a motor vehicle, and drive train module of said motor vehicle

A method for operating a drive train of a motor vehicle is provided, the drive train featuring a first drive assembly formed as an internal combustion engine a second drive assembly formed as an electric motor, a start-up element and a transmission). The start-up element features a converter and a lock-up clutch and is connected between the electric motor and the transmission. The electric motor is connected between the internal combustion engine and the start-up element. If a decoupling of the lock-up clutch is requested, the lock-up clutch of the start-up element is initially brought into slip. If the slip at the lock-up clutch of the start-up element reaches a threshold or is greater than the threshold, a target rotational speed is subsequently predetermined for the electric motor and the rotational speed of the electric motor is adjusted to such target rotational speed.

Transmission control method

A method of operating a drive train having a hybrid drive including a combustion engine and electric motor, a clutch located between the engine and the motor, a transmission, a starting element and a brake pedal. For electric crawling from a state in which the clutch is disengaged, the brake pedal is activated and the combustion engine is turned off, initially the starting element is brought to or maintained at a filling pressure. Next, the rotational speed of the electric motor is adjusted to be higher, by a defined slippage rotational speed, than a transmission side rotational speed. When this slippage is reached, the starting element is further engaged to create a crawl torque at the output. The electric motor continues at rotational speed control so that the slippage is maintained.

Method for operating a drivetrain

An method for controlling a parallel hybrid drive-train of a vehicle comprising an automatic transmission and a combustion engine which is connected, via a first shifting device, to an electrical machine, which is connected, via a drive shaft, a starting clutch positioned in the transmission. To guarantee safety and high drive comfort of the vehicle during failure of the starting clutch, shifting failures of the starting clutch are monitored. If a shifting failure is recognized, predetermined contingency procedures are initiated and executed in which either continued drive of the vehicle or slowing down of the vehicle to a stop is possible. A device comprises a monitor with a sensor and parts for analyzing and recognizing shifting failures of the starting clutch. Control parts initiate and execute contingency procedures such that a continued drive operation or slowing down of the vehicle to a stop is possible.

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Friedrichshafen, Germany

Falko Platzer