Zf Friedrichshafen Ag

Joachim Staudinger

Johannes Kemler

Maik Wurthner

Ingo Sauter

Peter Herter

Rainer Petzold

Franz Bitzer

Maik Wuerthner

Alexander Maier

Maik Würthner

Wolfgang Groener

Lutz Müller

Lutz Mueller

Maik WÜRTHNER

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 of controlling a rolling or a coasting function of a vehicle, such as a commercial vehicle, having a drive train including a drive motor, an automatic or automated transmission that is controllable by transmission controls, a controllable shifting mechanism for interrupting the flow of power in the drive train, and a driving speed control device. The flow of power in the drive train is interrupted in a suitable driving situation. In order for the rolling or the coasting function to be exploited as efficiently as possible, and still be terminated safely and comfortably, the flow of power in the drive train is restored depending on a selectable difference in speed (&#x394;v_F_T) between the current vehicle speed (v_F) and a speed limit (v_T) set by the driving speed control device.

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 controlling and/or regulating an automated transmission of a vehicle in which a rolling function or a coasting function of the vehicle is activated in an automatic mode, under predetermined conditions, such that the drivetrain is disengaged and the drive motor is one of operated at idle or is switched off at times. The rolling function or the coasting function is automatically terminated if at least one of the predetermined conditions is no longer present. The rolling function or the coasting function can also be terminated manually by the driver, and a manually operable shifting strategy can be initiated.

Method for controlling and/or regulating an automated transmission

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 operating a transmission positioned between a drive aggregate and an axle drive, a transmission input shaft is connected, via a clutch, with the drive aggregate, and a transmission output shaft is connected with the axle drive and power can be diverted from the transmission to drive a power take-off. The PTO is activated by an engine intervention, shifting the transmission to neutral and disengaging the clutch. Thereafter, the clutch is partially engaged at either a position dependent or distance dependent clutch speed while monitoring the input rotational speed and drive aggregate rotational speed. When the input rotational speed approximately equals the drive aggregate rotational speed and the idle rotation speed of the drive aggregate, the clutch is no longer being engaged at the position dependent or distance dependent clutch speed, but is fully engaged at a maximum clutch speed.

Method for operation of a transmission

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 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.

Growing community of inventors

Ravensburg, Germany

Joachim Staudinger