Siemens Aktiengesellschaft

Wolfgang Reupke

Manfred Wier

Stefan Krebs

Anton Angermaier

Bernhard Bauer

Michael Sudholt

Stephan Krebs

A method for emergency control of an internal combustion engine includes simulating signals (pulses or tooth signals are reference signals) of a crankshaft transducer from certain memorized variables, in the event of a failure of the crankshaft transducer. The memorized variables are the total number of teeth, angle lengths of segments (teeth, gaps) disposed on a crankshaft transducer disk, a transit time of the segments of the crankshaft transducer disk, and memorized crankshaft positions corresponding to edges of the segments.

Method for emergency control of an internal combustion engine

A method and an apparatus are provided for adapting air values from a substitute performance graph to currently prevailing variables of state of ambient air. The air values are used for controlling mixture preparation if pulsations of air occur in an intake tube of an internal combustion engine instead of using measured values supplied by an air meter. The air values are adapted by multiplying the air values by an adaptation factor. In one embodiment the adaptation factor is calculated by dividing a measured value supplied by the air meter in the intake tube of the internal combustion engine by an air value taken from the substitute performance graph and subjecting the adaptation factor to sliding averaging, at times when no pulsations are present; and using a lambda-control-average value as the adaptation factor and subjecting the adaptation factor to sliding averaging, at times when pulsations are present. In another embodiment the adaptation factor is calculated by taking a substitute air value from the substitute performance graph, multiplying the substitute air value by a temperature value, multiplying a reciprocal value of the multiplication by a measured value supplied by the air meter in the intake tube, and subjecting the result to sliding averaging, at times when no pulsations are present; and using a lambda-control-average value as the adaptation factor and subjecting the adaptation factor to sliding averaging, at times when pulsations are present.

Method and apparatus for adapting air values from a performance graph

A method for detecting combustion misfires includes calculating engine roughness values from fluctuations in crankshaft rpm, comparing the values with threshold values, and forming cylinder groups having an increased likelihood of misfiring. During a period of observation, each engine roughness value calculated for each cylinder is separately compared with a first threshold value and with a second threshold value being reduced in comparison with the first threshold value, a first counting sum associated with the cylinder is formed if the first threshold value is exceeded, and a second counting sum associated with the cylinder is formed if the second threshold value is exceeded. After the period of observation has elapsed, if the total sums of all of the first or second counting sums exceed a predeterminable total sum limit value, group sums are formed for each cylinder group from the second counting sums, and a conclusion is drawn as to the occurrence of a multi-cylinder misfire in the group having the higher group sum if the second counting sums of the individual cylinders in a group are approximately of equal magnitude, and conversely, if the second counting sums of the various cylinders are different, a conclusion is drawn as to a single-cylinder combustion misfire for the cylinder having the highest first counting sum, if the total sum of the first counting sums exceeds a predeterminable total sum limit value.

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Wuppertal, Germany

Wolfgang Reupke