Zf Friedrichshafen Ag

Johannes Kemler

Joachim Staudinger

Maik Wurthner

Ingo Sauter

Maik Wuerthner

Alexander Maier

Peter Herter

Rainer Petzold

Franz Bitzer

Franz-Josef Schuler

Rupert Kramer

Marcus Gansohr

Maik Würthner

Frank Deprez

Peter Spoerl

Maik WÜRTHNER

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 transmission () of a motor vehicle includes, in order to trigger a gear shift in the transmission (), determining a trigger speed depending on a response time of the gear shift to be implemented, depending on a gradient of a motor vehicle-side rotational speed, and depending on a maximum permissible limit speed for the motor vehicle-side rotational speed. The gear shift to be implemented triggered on a control side as function of the trigger speed such that the motor vehicle-side rotational speed does not exceed the maximum permissible limit speed during the implementation of the gear shift. The method also include adapting the trigger speed.

Method and control unit for operating a transmission of a motor vehicle

A method for operating a motor vehicle, the motor vehicle including a prime mover (), a transmission (), and a driven end (), wherein the transmission () is an automatic or automated transmission and is connected between the prime mover () and the driven end (). The method includes activating a sailing mode of the motor vehicle depending on at least one operating condition of the motor vehicle; performing a gear select interlock in the transmission (), while maintaining the sailing mode, when the sailing mode is active; and deactivating the sailing mode is subsequently depending on at least one operating condition of the motor vehicle. The gear select interlock is implemented in the transmission () depending on a rotational speed of the prime mover () and depending on synchronous speeds of the gears of the transmission ().

Method and control device for operating a motor vehicle

A method of shift control for an automatic transmission of vehicle power train, having a permanent brake between a drive motor and a final drive, in which current vehicle-specific, road-specific and driver-specific operating parameters, topographical data relating to an upcoming stretch of road ahead of the vehicle are determined while driving, and from which a tractive resistance value for the upcoming stretch of road is determined, and control commands for thrust downshifts and/or upshifts are derived and implemented, within the transmission, during a thrust operation depending upon the tractive resistance value. This is achieved in that the maximum permanent braking force curves that are possible for the upcoming stretch of road, in the currently engaged gear, and each adjacent gear is determined based on the current traveling and engine speeds and analyzed to derive control commands for a thrust downshift and/or upshift in relation to the tractive resistance value.

Method for controlling shifting in a semi-automatic gear transmission

A method of controlling an automated motor vehicle transmission. A current driving resistance is taken into account when selecting a target gear to be engaged as part of a shifting process. In order to be able to regulate shifting processes in a driving-resistance-dependent manner so as to ensure that the motor vehicle can always able to continue driving on, during selection of the target gear, disregarding gears for shifting from a currently engaged gear, in a driving-resistance-dependent manner, when the required associated shifting times are longer than a respective permitted maximum shifting time. In connection with the above, the method is incorporated in an automated motor vehicle transmission, a computer program product and a data carrier, containing the computer program product.

Method for controlling an automated motor vehicle transmission

A method of operating a drive-train which comprises an automated shift transmission having an unsynchronized main transmission and a synchronized downstream group that is drivingly coupled downstream from the main transmission. An input shaft of the automated transmission is connected, via a clutch, to a drive aggregate and an output shaft of the automated transmission is connected to a drive axle. When the vehicle is driven and the main transmission is in a neutral position, if the drive aggregate malfunctions, to engage a gear, the downstream group is adjusted to stop transmitting power and thereby coast to a stop. A shifting impulse is applied to a shifting cylinder of the main transmission so that shifting elements, of the main transmission, ratchet over one another and eventually mesh thus engaging the main transmission, and once the main transmission is engaged, the downstream group is brought to a power-flow-transmitting position.

Method for operating a drive train

A method of controlling a rolling or coasting function of a vehicle with a drive train having a drive motor, an automatic or automated transmission, a controllable shifting means, a brake device and a drive speed control device. The vehicle speed is regulated by the drive speed control device and the braking device is activated, as needed, when driving on a downhill gradient section. To effectively and reliably use the rolling or coasting function in suitable driving situations, taking into account the influence of the driving speed control device, a rolling or a coasting condition for a downhill gradient taper is checked, when driving on the downhill gradient section, and, when the rolling or coasting condition is satisfied, the transmission controls interrupt the flow of power in the drive train before the vehicle entering a flat area, and/or before the driving speed control device generates an engine torque request.

Method for controlling a rolling or coasting function of a vehicle

A method for controlling shifts in an automated multi-step variable-speed transmission, in a drive-train of a motor vehicle, between a drive engine in the form of an internal combustion engine and an axle drive. During driving, besides current vehicle, road and driver-specific operating parameters, topographical data relating to a road section ahead of the motor vehicle, in particular the road section height profile, are determined, and from this information, the driving resistance profile (FFW(xF)) of the motor vehicle for the road section ahead is determined. In the automatic mode of the multi-step variable-speed transmission, control commands for traction upshifts and/or traction downshifts are derived, during the traction operation, as a function of the driving resistance profile (FFW(xF)) and are implemented in the transmission. A limiting gear progression (GGr(xF)) is determined, which consists of the sequence of gears, and is evaluated for the derivation of control commands.

Method for controlling the shifting of an automatic geared transmission

A method of initializing the mass of a motor vehicle after a restart, for controlling a starting process of the motor vehicle a from a standstill. During operation of the motor vehicle, its mass is computed and the determined mass values are stored and, from the stored mass values, a vehicle-specific maximum mass value and/or a vehicle-specific minimum mass value is determined. The vehicle-specific maximum mass value and/or the vehicle-specific minimum mass value, determined in this manner, is subsequently used for initializing the mass of the motor vehicle after restarting the vehicle.

Method for initializing the mass of a motor vehicle

A transmission control device () for an automatic or automated transmission (). A shifting strategy of the transmission control device () controls and/or regulates the operation of the transmission () based on driving condition data such as vehicle mass, driving resistance, vehicle inclination, vehicle velocity, vehicle acceleration, engine rotational speed and/or engine torque, and based on data about the driver's wishes. The transmission control device () continuously calculates the driving condition data of the vehicle mass, driving resistance and/or vehicle inclination based on topographic data of a current position of the motor vehicle, and/or the shifting strategy determines a gear change from an actual gear into a target gear based on topographic data of a defined distance ahead of a motor vehicle. The defined distance ahead of the motor vehicle depends on the currently velocity of the vehicle.

Gearbox control device

A method of determining the size of a gear interval from a currently engaged gear to a target gear in a transmission. The method includes the steps of, for each current gear and for each possible gear interval from the current gear, recording a limit value for an acceleration or a deceleration in the target gear corresponding to the current gear and the respective gear interval used; for the current gear, starting with the smallest gear interval, applying a loop with successive increases of the gear interval to determine, depending on the current driving situation and characteristic parameters of the vehicle, the acceleration or the acceleration theoretically obtainable in the target gear produced by using the gear interval, which is compared with the respective recorded limit value until the acceleration or the deceleration theoretically obtainable no longer contravenes the limit value. The gear interval is then selected for a gearshift.

Method to define a gear step for a shifting

A method of operating a vehicle in a freewheel mode or a rolling mode, in which the vehicle has a drive train comprising a controllable drive engine, an automatic or automated transmission, and a controllable shifter for interrupting a flow of power in the drive train. To enable fuel-efficient and low-emission, as well as safe and comfortable driving, it is intended that the freewheel mode or the rolling mode is prognostically activated, deactivated or retained by performing a plausibility check of a currently active, automatic driving speed control function or a driving speed and a distance control function and/or other current driving operation or driving state data. The method includes coordinating and adapting relevant marginal conditions of the active driving speed control function or the driving speed and the distance control function, and of the freewheel mode or the rolling mode, according to the driving situation, and initiating control measures by a transmission control.

Method for operating a vehicle having a freewheel mode or a rolling mode

A method of controlling the driving mode of a motor vehicle, having a largely automated drive-train including a drive motor, a transmission and a separator clutch arranged between the motor and transmission, such that while driving, if certain operating conditions exist and a speed profile calculated with reference to topographical data and vehicle parameters for a road section lying ahead is suitable, the drive-train is disengaged and driving continues in a coasting mode until the occurrence of a termination signal. To enable coasting operation, the calculated speed profile for the case of immediate opening of the drive-train is determined continually at equidistant successive travel points along the driving stretch and is, in each case, evaluated in relation to lower and upper speed limits. Coasting is only enabled if, for a specified minimum number of successive travel points, the evaluation result is in each case positive.

Method for controlling the driving mode of a motor vehicle

A method of monitoring a hydraulic or pneumatic transmission control system, which comprises a pressure supply unit with a conduit directing a pressure medium under a supply pressure, and an actuating member for a clutch control element of a friction clutch. The actuating member has a pressure space which can be connected by a clutch control valve to the conduit, and in which the supply pressure is determined by a pressure sensor that can be connected to the conduit. The method includes the steps of determining the supply pressure by the pressure sensor, given that briefly opening the clutch control valve produces a pressure increase and/or a pressure gradient of the control pressure in the pressure space, and the currently existing supply pressure can be calculated from the control pressure, the pressure increase and/or the pressure gradient.

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Ravensburg, Germany

Johannes Kemler