Zf Friedrichshafen Ag

Dieter Neumann

Friedrich Tenbrock

Rainer Grundler

Christian Schwemer

Thomas Rossmann

Jens Wagner

A method for determining an oil condition, namely, an oil condition corresponding to the oil age or oil damage, with the following steps: a) measuring a temperature of the oil or of the part through which the oil flows, coordinating each temperature measured with one temperature range defined by an upper limit and/or a lower limit; b) as soon as the measured temperature exceeds or falls below a limit of a temperature range, measuring the period of time during which the measured temperature dwells in this range; c) in addition, integrating an oil flow running during this time over the time period measured in step b); d) from the time period measured in step b) and the integral of the oil flow determined in step c), determining an oil age or oil damage characteristic for the current temperature range.

Method for determinating of an oil condition

The invention relates to a method for regulating an electrohydraulically controlled clutch or a brake of a transmission. According to the invention, the clutch or brake is regulated using a model-based compensation pressure regulator with the help of an observation unit, whereby the compensation-pressure control circuit contains a non-linear compensation element which corresponds to the inverse model of the control system of the coupling or brake. The observation unit estimates interference levels of the clutch regulation from a drive chain model, according to a condition-estimation procedure.

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Neukirch, Germany

Dieter Neumann