Bayerische Motoren Werke Aktiengesellschaft

Zf Friedrichshafen Ag

Markus Pfisterer

Matthias Reichler

Roland Neubaur

Arman Kara

Florian Hannemann

Wolfgang Fickler

A method for operating a drive train having a starting component between an electric machine and an output shaft of a transmission, and a separating clutch between an internal combustion engine and the electric machine, with a rotor of the electric machine being coupled to the input shaft of the transmission, where the method initially drives a motor vehicle solely by the electric machine while the starting component is engaged or slipping and the separating clutch is disengaged. The method then engages the separating clutch to crank the internal combustion engine. The method disengages the separating clutch after cranking, with an output-side rotational speed of the separating clutch being lower than an idling speed of the internal combustion engine. Subsequently, the method engages the separating clutch to drive the motor vehicle with the internal combustion engine when a target drive torque reaches or exceeds a limit.

Method for operating a motor vehicle drive train and electronic control unit for carrying out said method

Gear-changing quality of a motor vehicle having an automatic transmission in which filling pressure adaptation processes are carried out by an electronic control device by predefined activation of an oil pump and selected hydraulic switching elements is improved by inclusion of a minimum time margin between the individual adaptation processes predefined by the control device such that parallel adaptation processes are prevented.

Method and device for improving the gear-changing quality of a motor vehicle having an automatic transmission

The method according to the invention for shift point control in automatic transmissions by means of an electronic control device, which receives a performance requirement value and the vehicle speed as input signals and triggers up-shifts and down-shifts, by means of a functional module. The functional module controls the shift point, by using characteristic shift curves stored in the control device as a function of the performance requirement value and the vehicle speed. When predetermined operating conditions apply, a speed range is defined below a defined vehicle speed, in which range an instantaneous down-shift is performed, which is independent of the currently applicable characteristic shift curve. As soon as the performance requirement value or an operating value proportional to the performance requirement value falls below a threshold, an up-shift subsequent to the down-shift is delayed by a first predetermined time period after the instantaneous down-shift.

Method for controlling a shift point in an automatic transmission

A device and method for indicating the engine speed of a motor vehicle is provided. The engine speed in a motor vehicle is displayed, during a gear speed change via an engine speed signal, which is independent of the detected engine speed signal that is output as the engine speed signal, which is to be displayed, to the engine speed display module by way of an electronic transmission control module in the vehicle.

Device and method for indicating the engine speed in a motor vehicle

For controlling an automatic transmission having an electronic control unit and having a power control element, the control unit detects a desired-power signal corresponding to the position of the power control element and, basically as a function of this desired-power signal, causes a change of gear corresponding to the characteristic shifting curves stored in the control unit. The control unit also generates a gradient signal corresponding to the rate of change of the desired-power signal and can&#x2014;when certain conditions exist&#x2014;cause a backshift deviating from the characteristic shifting curves as a function of this gradient signal. By way of the control unit, an immediate multiple backshift is initiated as a function of the gradient signal when, as a characteristic shifting curve for a first backshift has been reached, the gradient signal has exceeded at least a first lower limit value.

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Puchheim, Germany

Markus Pfisterer