Volkswagen Ag

Conti Temic Microelectronic Gmbh

Edgar Bothe

Wolfgang Schreiber

Uwe Hinrichsen

Volker Gärtner

Armin Tonn

Axel Schamscha

Stephan Schaefer

Alwin Becher

Andreas Schwenger

Klaus Leipnitz

Henning Müller

Johannes GRÜNEWALD

Romina Feldhaus

Mathias Neumann

Sascha Neudörfer

Load change impacts in a motor vehicle, especially as a result of abrupt changes in the position of the accelerator pedal, are prevented with the novel method. At least one dual clutch mechanism is provided between the drive engine and the gearbox. The gearbox has several selectable gear steps and the clutch is controlled in relation to the torque that is to be transmitted. The driving comfort is improved by controlling the clutch during the starting process of the motor vehicle and/or the gear steps are engaged during the starting process of the vehicle in such a way that the speed of rotation of the gear input shaft is lower than the idling speed of rotation of the engine.

Method for preventing load change impacts in a motor vehicle

A method actuates two clutches which transmit torque in parallel in a drive train of a motor vehicle and have different successive fixed speed transmissions as gear stages between a drive shaft and an output shaft. The clutches are triggered during acceleration processes of the motor vehicle that both clutches simultaneously transmit torques and a resulting transmission of torque takes place continuously between the drive shaft and the output shaft. The rotational speed of the drive shaft is greater than the respective rotational speed of the respective transmission input shaft of the respective partial train at the secondary end of the respective clutch during the entire starting process, or the rotational speed of the drive shaft is greater than or the same as the respective rotational speed of the respective transmission input shaft of the respective partial train at the secondary end of the respective clutch during an acceleration process.

Method for the actuation of at least two clutches transmitting torque in parallel in the drive train of a motor vehicle and transmission control unit

Gear shifts are carried out from a source gear to a target gear of a twin clutch transmission. The twin clutch transmission has sequentially directly successive gears assigned to different transmission input shafts. In each case one upshift and downshift threshold, which is defined as a function of the throttle pedal position, for each possible sequential gear change is stored as a corresponding vehicle speed value in a control unit. In case of a commanded downshift from a source gear to a lower gear, the target gear is determined in that the current vehicle speed is initially compared with the limit value of the closest downshift threshold, or of the adjacent downshift thresholds in the downshift direction, until the current vehicle speed is higher than the respective limit value of the most recently checked downshift threshold, in that, if, at the most recently checked downshift threshold, the higher gear of the downshift threshold is assigned the same transmission input shaft as the source gear, then the current vehicle speed is compared with the limit value of the upshift threshold which corresponds to the most recently checked downshift threshold. When the current vehicle speed is higher than the limit value of the upshift threshold, the higher gear of the upshift threshold is selected as a target gear. If the vehicle speed is lower than the limit value of the upshift threshold, the lower gear of the upshift threshold is selected as a target gear.

Method for shifting from a source gear to a target gear in a twin clutch transmission

A method and a device for controlling a motor vehicle drive train determine the direction of rotation of the drive train by evaluating sensor signals of a first sensor unit on the output side of the drive train. The first sensor unit includes a sensor wheel fastened to a rotatable component on the output side of the drive train and two rotational speed sensors which are fixed with respect to a housing and are placed circumferentially next to one another. In order to speed up the determination of the direction of rotation, the sensor signal of a second sensor unit on the input side of the drive train is evaluated. The second sensor unit includes a sensor wheel that is fastened to a rotatable component on the input side of the drive train and a rotational speed sensor that is fixed with respect to the housing.

Method and device for controlling a motor vehicle drive train

A method for a shift control of a power shift transmission includes closing an incoming, engaging clutch unit assigned to a new gear and opening the outgoing, disengaging clutch unit assigned to an old gear such that the closing and the opening overlap in time. The incoming clutch unit is closed after performing a filling operation for providing a filling pressure for the incoming clutch unit. The filling operation is concluded by a filling end. In case of a manually triggered power shift, the filling operation for the incoming clutch unit is performed with an increased filling pressure corresponding to an order of magnitude of the clutch capacity of the outgoing clutch unit. After the filling end is identified, the outgoing clutch unit is opened and, overlapping in time, a clutch capacity of the incoming clutch unit is adapted.

Method for a shift control of a power shift transmission

A method for controlling the shifting operation of an automated twin-clutch transmission includes executing a shifting operation between a load gear and a target gear assigned to a first transmission unit by using an intermediate gear assigned to a second transmission unit. The engine speed is adjusted to reach the synchronous speed of the target gear at the end of the shifting operation. At the start of the shifting operation an initial target speed gradient is set such that the engine speed reaches the synchronous speed at the end of the shifting operation based on an estimated total shifting time. The actual shifting progress is determined during the shifting operation and is compared with the estimated shifting progress. The target speed gradient is adjusted to the actual shifting progress in case the actual shifting progress and the estimated shifting progress deviate from one another.

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Peine, Germany

Edgar Bothe