Zf Friedrichshafen Ag

Michael Gromus

Bernd Allgaier

Friedrich Tenbrock

Johannes Kaltenbach

Peter Schiele

Thomas Lemp

Ralf Dreibholz

Stefan Blattner

Gerd Frotscher

Stefan Kilian

Claus Granzow

Christian Schwemer

Robert Zdych

Martin Neumann

Klaus Habe

A method for operating a hybrid vehicle comprises conducting unfire operation in an internal-combustion engine in a fuel cut-off mode during a hybrid-mode ride in deceleration of the internal-combustion engine, disconnecting the internal-combustion engine from an output while maintaining the fuel cut-off mode, and reducing a transmission capacity of a clutch configured to couple the internal-combustion engine and an electric motor. During a hybrid-mode ride in deceleration of the internal-combustion engine for transition to the purely electric drive, the internal-combustion engine may be disconnected from the output and shut down. When the internal-combustion engine is operated unfired in a fuel cut-off mode, the internal-combustion engine may be disconnected from the output and shut down by reducing the transmission capacity of the clutch that is connected between the internal-combustion engine and the electric motor.

Method and system for operating a hybrid vehicle

A method of operating a drive train of a motor vehicle in which the drive train comprises at least a hybrid drive with an internal combustion engine and an electric motor, a clutch connected between the combustion engine and the electric motor, a transmission arranged between the hybrid drive and a drive output, and preferably a transmission-internal or -external starting element. When the combustion engine is entrained into motion with the help of the electric motor, the clutch connected between the internal combustion engine and the electric motor is partially engaged to a slipping condition where the clutch transmits a constant torque, and during this entrainment, and comparing an actual gradient of the combustion engine's speed produced with a nominal gradient of the combustion engine's speed. When the actual gradient is greater than the nominal gradient, the method concludes that the combustion engine is started and actively providing torque.

Method for operation of a drive train

A transmission control device () of a transmission () for a drivetrain which includes, in addition to the transmission (), a hybrid drive with an internal combustion engine () and an electric motor (). The transmission control device () stores parameters which form the basis of the manner with which gearshifts are controlled or regulated. At least some parameters are stored in duplicate, firstly, for operating the transmission () under purely electric-motor power using only the electric motor (), and secondly for operating the transmission () during hybrid driving using both the internal combustion engine () and the electric motor ().

Transmission control device

A method of operating a drivetrain of a motor vehicle which comprises a hybrid drive with a combustion engine coupled by a clutch to an electric motor. To start the combustion engine with the electric motor, the clutch is partially engaged to a slipping condition to deliver electric motor torque from a starting value, the torque transmitted by the clutch is increased to a first final value. If during this, the combustion engine begins turning, the break-away torque of the internal combustion engine is determined. If the combustion engine does not begin turning, the clutch is further engaged to a slipping condition starting from a second initial value, such that torque transmitted by the clutch increases linearly until the combustion engine begins turning, and the break-away torque of the internal combustion engine is determined from the clutch torque at which the combustion engine begins turning.

Method for operating a drive train

A method for actuating a continuously variable clutch such that the torque to be transmitted by the clutch is continuously adjusted either electromechanically via an electromotive drive, hydraulically via a pressure actuator, or electromagnetically via an electromagnetic actuator. The torque transmitted by the clutch is adjusted by utilizing a position-dependent clutch torque specification.

Method for activating a clutch

A method of controlling a hybrid drive train of a vehicle which comprises, in series, an internal combustion engine, a clutch, an electric motor and a transmission with an output connected to the drive axle. During traction operation, the vehicle changes from an electric driving mode into a combination driving mode or a combustion engine driving mode, in that the clutch is engaged and the electric torque is temporarily increased. The method includes regulating engagement of the clutch at least until reaching a starting rotational speed of the combustion engine such that the acceleration of the combustion engine occurs according to a predetermined progression of rotational speed and that the torque of the combustion engine is increased by the same amount as the transferable torque of the clutch is increased by the engagement process.

Method to control a hybrid drive train

A method for controlling a hybrid drivetrain of a motor vehicle such that, during a thrust operation of the vehicle, a change takes place from a combustion-powered driving mode, in which the combustion engine is in a thrust operation, the separator clutch is engaged and the electric machine contributes no force, or from a combined driving mode in which the engine is in a thrust operation, the clutch is engaged and the electric machine operates as a generator, to an electric driving mode in which the engine is switched off, the clutch is disengaged and the electric machine operates as a generator. To efficiently change driving modes, the clutch is partially disengaged to a slip limit; the clutch is then completely disengaged; and when the clutch reaches the slip limit, the generator torque of the electric machine is increased inversely to the torque that can be transmitted by the clutch.

Method for controlling a hybrid drivetrain

A method for operating a parallel hybrid drive train of a vehicle having an internal combustion engine, an electric engine and an output. The electric engine being located in the power drive between the output and the internal combustion engine. A second shifting element is located between the internal combustion engine and the electric engine and a first shifting element between the electric engine and the output. Output torque driving the output can be adjusted according to the transmitting capacities of the first and second shifting elements and according to the input torque of the electric engine and/or internal combustion engine. These adjustments are corrected according to standards derived from divergences found in parameters during operation of the drive train.

Method for operating a parallel drive train of a vehicle

A method for operating a parallel hybrid powertrain () of a vehicle having one internal combustion engine () and one electric motor (). The electric motor is located in the drivetrain between an output and the internal combustion engine. Between the internal combustion engine and the electric motor, a frictionally engaged shifting element is provided, while between the electric motor and the output, a starting element () having a hydrodynamic torque converter (A) and a converter lock-up clutch (B) is disposed. A target output torque to be applied to the output is dependent on the slippage of the starting element. During a starting phase of the internal combustion engine via the electric motor, an input torque produced by the electric motor is directed at least in part via the torque converter and in part via the converter lock-up clutch.

Method for operating a parallel hybrid powertrain of a vehicle with at least one internal combustion engine and at least one electric motor

A method is described for operating a parallel hybrid device train () of a vehicle having an internal combustion engine (), an electric engine () and an output () wherein the electric engine () is disposed in the power train between the output () and the internal combustion engine () and both between the internal combustion engine () and the electric engine () and between the electric engine () and the output () is respectively provided a frictionally engaged shifting element (). In addition, a nominal output torque abutting on the output () can be adjusted according to the transmitting capacity of the first shifting element () located between the electric engine () and the output (). According to the invention, the transmitting capacity of the first shifting element () is adjusted under control according to the nominal input torque required so that the first shifting element () has a transmitting capacity needed for producing the nominal output torque on the output (). Furthermore, an input rotational speed of the electric engine () is adjusted under regulation during a starting process of the internal combustion engine () in order to keep the first shifting element in slip operation at least during the starting process of the internal combustion engine () and to produce the nominal output torque on the output ().

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Eriskirch, Germany

Michael Gromus