Fichtel & Sachs Ag

Mannesmann Sachs Ag

Bmw Ag

Thomas Kuhn

Hans-Joachim Schmidt-Brucken

Thomas John

Wolfgang Nehse

A device for controlling a starting procedure of a motor vehicle for initiating a movement of the motor vehicle includes a controller which receives as input, signals generated by an engine shaft speed sensor, a driving speed sensor, a transmission shaft speed sensor, a transmission output shaft speed sensor, and an accelerator pedal position sensor. The controller is operatively connected to the engine for increasing the engine speed above a minimum threshold value when the driver signals his desire for a racing start. The controller is also operatively connected to a clutch activation device for deliberately producing a slip of the driving wheels and for controlling the slip of the driving wheels by controlling a slip of the clutch after a starting time point signaled by the driver.

Device for controlling a starting procedure

A slip control loop (13) is proposed which compares the actual differential speed between input and output speed of a friction clutch (5) of a motor vehicle with a desired differential value and adjusts a positioning drive (7) of the clutch (5) according to the desired differential speed. To increase the accuracy of control, a desired position signal from a clutch characteristic curve memory (25) is additively superimposed in the sense of an influencing variable on the desired position signal s' calculated by a controller (19) of the slip control loop (13). The clutch characteristic curve memory (25) stores the desired position signal s' as a function of the clutch moment which can be transmitted in this position and is addressed according to the instantaneous engine moment determined, for example, via an engine characteristic map (27). During a load change of the engine (1), the clutch (5) is adjusted to the expected moment before a significant change in the actual differential speed occurs. The controller (19) has an integrating controller property so that the integral portion of the desired signal s' is zero when the dimensioning of the clutch characteristic curve stored in the clutch characteristic curve memory (25) is corrected. A correcting device (33) allows step-wise correction of the characteristic curve as a function of the value of the integral portion.

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Bad Kissingen, Germany

Thomas Kuhn