Zf Friedrichshafen Ag

Ingo Sauter

Maik Wurthner

Werner Wolfgang

Joachim Staudinger

Johannes Kemler

Maik Würthner

Peter Herter

Melchor Moro-Oliveros

Rupert Kramer

Thomas Hafen

Maik Wuerthner

Michael Burkhart

Achim Tegen

Maik WÜRTHNER

Wemer Wolfgang

A method of decoupling a power take-off drive of a motor vehicle transmission during travel of a motor vehicle in which a form-locking shift element of the power take-off drive is controlled for disengaging the power take-off drive. To implement reliable decoupling without interrupting travel of the motor vehicle, if disengagement of the shift element initially did not occur, control of the shift element is immediately implemented the next time a separating clutch, placed between the motor vehicle transmission and a drive engine of the motor vehicle, is actuated and/or a connection of the shift element toward an output side of the motor vehicle transmission is interrupted, over the course of a subsequent gear shift in the motor vehicle transmission. A drive train of a motor vehicle, a computer program product, and a data carrier having the computer program product.

Method for decoupling a power take-off of a motor vehicle transmission while driving a motor vehicle

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 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

The invention concerns a method for controlling a motor vehicle drivetrain which comprises a drive motor, a multi-step, automated change-speed transmission and an automated separating clutch arranged between the drive motor and the transmission, and a shifting device with a selector lever which can be moved at least from a particular position in an upshift direction ('+' direction) for manually initiating an upshift and in a downshift direction ('&#x2212;') for manually initiating a downshift, and in which the transmission and the separating clutch can be controlled by a transmission control unit which is connected at least to a speed sensor, a brake pedal actuation sensor and a selector lever actuation sensor, such that when the motor vehicle is rolling with its drivetrain open the closing of the drivetrain is initiated by actuating the selector lever. To improve the functional safety it is provided that when a first movement of the selector lever in a shift direction (&#x201c;+&#x201d; direction or &#x201c;&#x2212;&#x201d; direction) is sensed, this is interpreted as a provisional command to close the drivetrain, and if a second movement of the selector lever in the same shift direction (&#x201c;+&#x201d; direction or &#x201c;&#x2212;&#x201d; direction) is sensed within a specified confirmation time (&#x394;t), this is interpreted as a confirmation of the provisional command to close the drivetrain and, as an implementation command, initiates the closing of the drivetrain.

Method to control a motor vehicle power train

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 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 for automatically determining a current offset value for the zero-point correction of a vehicle inclination sensor including the steps of while driving in a first driving direction, the current driving resistance is determined repeatedly, without regard to the sensor and stored temporarily, and a current raw signal value of the sensor is noted. Upon a change in the driving direction, the last-noted raw signal value is stored temporarily and while driving in the second driving direction. The current driving resistance is determined repeatedly, without regard to the sensor and stored temporarily. Then, if the difference between the two stored driving resistances agree with a tolerance threshold, the noted raw signal value is stored as the offset value for the zero-point correction of the inclination sensor.

Method for calibrating a slope sensor

A method of controlling an automated multi-step change-speed transmission of a vehicle having an electronic control unit connected to sensors for detecting operating parameters and to gear and/or clutch control elements for carrying out shift operations. The control comprises a data memory such that the multi-step change-speed transmission can be operated automatically to initiate gearshifts in an automatic mode, manually initiated by a driver in a manual mode to provide gearshifts, and manually actuated in a learning mode in which gearshifts and operating parameters can be recorded automatically. When necessary to assist technicians in the application of the transmission, a configuration-learning mode that can be activated in which, during a test drive with manual gearshift initiation, operating parameters are automatically detected in an event-dependent manner, processed to produce control data for the transmission, and the control data stored in the data memory for the future control of the transmission.

Method for controlling an automated multistep change-speed gearbox

A method for controlling a drive train of a motor vehicle comprising a drive engine, an automated transmission, and an automated clutch arranged in the force flow between the drive engine and the transmission. In order to achieve low component wear, a comfortable coasting operation mode and a spontaneous transition into the traction mode, it is provided that additional coast downshifts are prevented as soon as the driving speed (v) of the motor vehicle has reached or dropped below a previously defined threshold speed (v) for coast downshifts (v&#x3c;=v), or the currently engaged gear (G) corresponds to a previously defined limit gear (G) for coast downshifts (G=G) and, after dropping below the threshold speed (v) or after engaging the limit gear (G), a transition into the traction mode is prepared by determining a current target gear (G) and an associated shifting speed (n) of an adaptive shift for the transition into the traction mode as a function of the driving speed (v) of the motor vehicle and/or the engine speed (n) of the drive engine.

Method for controlling a drive train of a motor vehicle

A method and device for provisionally determining the mass of a vehicle when it is initialized. After initialization of the vehicle, the method determines a vehicle mass value by a static mass determination method and then checks whether this value is within a predetermined tolerance band around the dynamically last-determined vehicle mass value, which has been stored for that purpose. If this is so, and there has in the meantime been no significant change of the vehicle's mass, the previously stored dynamic vehicle mass value is probably more accurate and is used in the determination. Otherwise it can be assumed that the vehicle mass value has changed substantially, and the statically determined vehicle mass value is therefore used until a device for the dynamic determination of a vehicle mass can supply a more accurate vehicle mass value after a short time.

Determination of the mass of a vehicle

A method for controlling gear shifts in an automated stepped gear transmission of a motor vehicle in which operating parameters of the motor vehicle are continuously determined and evaluated for initiating and carrying out a shift from a currently engaged gear to a target gear such that, before a shift, the shift speed for initiating the shift and the target gear are determined. For better adaptation of the shift, in particular the determination of the shift speed and the target gear, to the current driving and operating conditions of the motor vehicle, the shift types 'shift-speed-orientated shift' and 'target-speed-orientated shift' are provided and, immediately before a shift operation, it is decided, as a function of at least one of the operating parameters in which, of the two shift types, the shift is to be carried out.

Method for controlling shifting of a stepped automatic transmission

A process of controlling and/or regulating an automatic transmission in which a predetermined shifting speed of the gear shift is carried out and adjusted during a shift program, and in which the detection of a constant-speed driving of the vehicle is carried out at least during the shift program.

Method for controlling and/or regulating an automatic gearbox

A method for determining the driving resistance of a motor vehicle simultaneously with a shift of an automated shift transmission from a load gear to a target gear such that if a difference between a first driving resistance value F_fw_1 and a second driving resistance value F_fw_2 is large, the shift operation can be corrected. The second driving resistance value F_fw_2 is determined during the shift operation. a time interval &#x394;t which contains the traction-force-free phase of the shift, a plurality of acceleration values a_i of the motor vehicle are measured to obtain the minimum acceleration a_min if the shift operation is a traction shift or the maximum acceleration a_max if it is thrust shift. With the mass m of the vehicle, the second driving resistance value F_fw_2 is calculated with one of the formula F_fw_2=&#x2212;m*a_min or F_fw_2=&#x2212;m*a_max.

Growing community of inventors

Meckenbeuren, Germany

Ingo Sauter