Zf Friedrichshafen Ag

Frank Deprez

Christoph Köhler

Jens Kastens

Johannes Kemler

Felix Bühle

Holger Bacher

Florian Mayer

Pablo Ole Schmidt

A method for operating a hybrid vehicle includes, depending on a presence of a control-side demand to engage a separating clutch (), implementing an engagement process of the separating clutch () during driving under purely electric motor power and, depending on the presence of a control-side demand to implement an upshift in a transmission (), implementing a gear ratio change from a current gear of the upshift into a target gear of the upshift. In response to the control-side demand to engage the separating clutch () and the control-side demand to implement the upshift, the method includes checking whether the upshift is necessary in order to prevent a vehicle-side rotational speed from reaching or exceeding a rotational speed limit value. When the upshift is necessary in order to prevent the vehicle-side rotational speed from reaching or exceeding the rotational speed limit value, the implementation of the upshift in the transmission is prioritized over the implementation of the engagement process of the separating clutch.

Method and control unit for operating a hybrid vehicle

A method for operating a power shiftable transmission of a motor vehicle, the transmission including a control unit, an input shaft, an output shaft, a gear set, and multiple shift elements, the method including transmitting, with the control unit, a request for a reduction of a drive torque acting on the input shaft for carrying out an upshift, and determining, with the control unit, whether the reduction is completely possible, partially possible, or impossible based on a signal. When the reduction is completely possible, the method includes controlling, with the control unit, a torque transmission rate of a shift element of the multiple shift elements to be engaged during the upshift according to a first way. When the reduction is partially possible or impossible, the method includes controlling, with the control unit, the torque transmission rate according to a second way, the second way differing from the first way.

Method and control unit for operating a power-shift transmission

A method for operating a hybrid vehicle having a prime mover including an internal combustion engine and an electric machine, the vehicle further having a transmission connected between the prime mover and a driven end and including multiple shift elements, the vehicle further having a separating clutch connected between the internal combustion engine and the electric machine, and a starting component which is provided by a separate launch clutch or by a shift element of the transmission. The method includes monitoring a rotational speed of one of the internal combustion engine, the electric machine, the transmission, or the driven end during travel with the internal combustion engine running and the separating clutch engaged. The method further includes determining an increase in driving resistance, and decoupling the internal combustion engine when the monitored rotational speed falls below or reaches a first limiting value by disengaging the separating clutch.

Control method and control unit for a hybrid vehicle

A method for operating a drive train of a motor vehicle with a prime mover () including an internal combustion engine () and an electric machine (), a separating clutch () connected between the internal combustion engine and the electric machine, and a transmission () connected between the prime mover () and a driven end () is provided. When at least one first operating condition is present, a previously decoupled internal combustion engine () is coupled such that the separating clutch () is actuated to engage. When at least one second operating condition is present, the coupling of the internal combustion engine is aborted, and an absolute value of a torque currently transmitted or currently transmittable by the separating clutch () is determined. The separating clutch () is disengaged at different rates depending on the absolute value of the torque currently transmitted or currently transmittable by the separating clutch ().

Method and control system for operating a drive train

A method for operating a motor vehicle includes, when a target differential speed is set for a separating clutch (), determining a power transmission factor depending on the target differential speed and an internal combustion engine-driven torque to be transmitted by the separating clutch (). The method also includes determining an actuating pressure for the separating clutch () depending on the power transmission factor, controlling the separating clutch () with the actuating pressure, ascertaining an actual differential speed forming at the separating clutch () depending on the actuating pressure, determining a corrected power transmission factor with a controller () depending on a deviation between the target differential speed and the actual differential speed, determining a corrected actuating pressure for the separating clutch () depending on the corrected power transmission factor and the internal combustion engine-driven torque to be transmitted, and controlling the separating clutch () with the corrected actuating pressure.

Control unit for a motor vehicle, and method to control the motor vehicle

A method for controlling a hydraulically actuated shift element of a vehicle transmission (G) includes determining a fill level of a pressure compensating cavity () associated with a pressure chamber () and controlling pressurizing of the pressure chamber () with hydraulic fluid based at least in part on the determined fill level of the pressure compensating cavity (). The pressure chamber () is fillable with the hydraulic fluid by an electronically controlled hydraulic system in order to actuate the shift element.

Method for controlling an hydraulically actuated shifting element of a vehicle transmission

A method for controlling torque transfer of a force-fitting shift element includes controlling a closing pressure at least temporarily upon presence of a closing request for the force-fitting shift element and when a prevailing system pressure of the hydraulic circuit is above a threshold value for the system pressure. The closing pressure is controlled in a manner that is different than upon the presence of the closing request for the force-fitting shift element and when the prevailing system pressure is below the threshold value for the system pressure.

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Mariabrunn, Germany

Frank Deprez