Siemens Aktiengesellschaft

Siemens Aktiengesell Schaft

Manfred Wier

Anton Angermaier

Thomas Vogt

Stefan Treinies

Anton Angermeier

Bernhard Bauer

Maximilian Engl

Hartmut Pfleger

Wolfgang Reupke

Michael Suedholt

Michael Sudholt

Erwin Achleitner

Hellmut Freudenberg

Klaus Bayerle

Stefan Krebs

Alexander Ketterer

Siegfried Ellmann

Thomas Elbe

Guenter Scheid

Stephan Krebs

Pulsations which falsify an output signal of an air mass meter occur at low and medium rotational speeds in a unit that supplies air to an internal combustion engine. A method for adjusting the load of the internal combustion engine limits an opening angle of an electromotively adjustable throttle valve to a rotational speed-dependent opening value which includes an opening base value that is between a lower and an upper limit value. In the case of the lower limit value, the full load of the engine is reached. In the case of the upper limit value, pulsations of the air in an intake duct upstream of the throttle valve do not yet occur.

Method for adjusting the load of an internal combustion engine, in

During lean operation of the internal combustion engine, preferably in relatively long-lasting overrunning shutoff phases, the output voltage of the sensor signal is regulated to a predetermined desired value via the heating control unit. If within the diagnosis period, fewer than a predeterminable number of monitoring results are within a tolerance range located around the desired value, then the heating circuit is classified as defective.

Method for monitoring the functional capability of an exhaust gas

Process for checking the conversion capability of a catalyst

Diagnostic method for recognizing combustion misfiring in an

A method for adapting a starting injection timing to a pressure of ambient air includes storing in memory a correction factor representing an ambient air pressure when an engine is turned off. A value for a starting injection timing is modified with the correction factor, upon a starting process.

Method for correction of starting injection timing

A method for monitoring functional capability of a tank venting system for a motor vehicle, includes evacuation of the tank venting system through the use of negative pressure or vacuum prevailing in the suction tube of an internal combustion engine and assessing the system based on negative pressure buildup and negative pressure letup gradients. Additionally, besides other abnormal termination criteria, the dynamics of pressure changes are also monitored and the method is immediately discontinued, if pressure fluctuations are ascertained which exceed a predetermined measure.

Method for monitoring the functional capability of a tank venting system

A method for detecting bad stretches of road includes ascertaining a tripping variable representing acceleration of at least one wheel of a vehicle. A bad stretch of road is detected if the amount of the tripping variable exceeds a predeterminable limit value. The tripping variable is dependent on at least two segment times that the wheel needs to pass through associated angle segments.

Method for detecting stretches of bad road

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

The method and associated apparatus ascertain an air value which is used in the mixture preparation in the event of pulsations of air in the intake tube of an internal combustion engine. During each intake stroke of a cylinder of the engine, a maximum value and a minimum value of an air flow are ascertained from measured values furnished by an air flow rate meter. A differential value is formed from a magnitude of the two extreme values. And the differential value is compared with a predeterminable threshold value. For air/fuel mixture is prepared on the basis of the air value. If certain conditions apply, the processor switches over from the measured values furnished by the air flow rate meter to predetermined substitute values from a substitute performance graph. The conditions which must be met for the switchover are that (a) the differential value is greater than the threshold value, (b) the throttle valve is opened by an angle greater than a predetermined angle, and (c) the engine is not in a non-steady operating state.

Airflow error correction method and apparatus

A method for detecting combustion misfires in internal combustion engines includes calculating a non-concentricity value from fluctuations in angular speed of a crankshaft, and dropping the non-concentricity value below a negative non-concentricity limit value if a combustion misfire is present. If the non-concentricity value drops below the non-concentricity limit value, a value for a stretch of bad road is calculated from successively calculated non-concentricity values, and the value for a stretch of bad road is dropped below or made of equal magnitude to a positive limit value for a stretch of bad road, if a stretch of bad road is present. The previously indicated combustion misfire is not confirmed if the value for a stretch of bad road drops below or is of equal magnitude to the limit value for a stretch of bad road. However, the previously indicated combustion misfire is confirmed if the value for a stretch of bad road exceeds the limit value for a stretch of bad road.

Method for combustion misfire detection with bad road detection

A method for recognizing stretches of rough or bad road includes recognizing tank pressure values at successive evaluation instants. A change in tank pressure is ascertained from successive tank pressure values. A stretch of rough or bad road is recognized if the change exceeds a limit value.

Method for recognizing stretches of rough road with the aid of a tank

Method for recognizing irregular combustions in a cylinder of an

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.

Method for detecting combustion misfires in a plurality of cylinders

A method for suppressing vibration in the drive train of a motor vehicle includes detecting an rpm of a vehicle engine; deriving an rpm gradient from the rpm and evaluating the rpm gradient; and reducing torque of the engine by varying an ignition angle if impermissible vibration is detected, wherein the torque reduction is controlled as a function of an upper and a lower limit value for the rpm gradient. The ignition angle is retarded if the rpm gradient drops below the lower limit value; switching back to an initial performance graph takes place if the rpm gradient exceeds the upper limit value; and the upper and the lower limit values are predetermined as a function of the engine rpm.

Method for suppressing vibrations in the drive train of a motor

A method is provided for recognizing erratic combustion in a multicylinder internal combustion engine by using a time measuring device to measure successive time periods which a crankshaft needs to rotate through predetermined angles during operating strokes of successive cylinders. The method includes determining a static component by using a calculating device to subtract a time period of the next cylinder in an ignition order from the time period of a cylinder to be examined. The static component is multiplied with a standardizing factor by using the calculating device. A dynamic component is determined by using the calculating device to subtract a time period of a next cylinder in the ignition order from a time period of a preceding cylinder in the ignition order, and a dynamic component is negated. A change component for a lack of smoothness value is formed, the lack of smoothness value is multiplied with a weighting factor to form a weighted value, and the weighted value is set equal to zero if the weighted value is negative. A sliding average is formed from the weighted value in a sliding averaging process. A lack of smoothness value is determined from addition of the static component, the dynamic component, and the sliding average. A combustion misfire is recognized if the smoothness value falls below a given limit value.

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Wenzenbach, Germany

Manfred Wier