Robert Boschgmbh

Andrea Lohmann

Michael Lehner

Klaus Ries-Muller

Jurgen Forster

Michael Baeuerle

Klaus Ries-Mueller

Stephan Uhl

Heiko Oertel

Martin Klenk

Manfred Mezger

Asmus Volkart

Peter Wiltsch

Wolfgang Wimmer

Helmut Gross

Robert Seyfang

Sigrid Hafner

Hans Barho

Juergen Schwabe

Martin Bulla

Uwe Buck

Ralf Schnee

Heinz Viel

A method for detecting combustion misfires in internal combustion engines on the basis of an evaluation of the segment times is introduced wherein a shaft of the engine passes over predetermined angular segments. The method is characterized by variable segment lengths and/or segment positions relative to a reference point of the movement of the pistons of the engine. The position of the angle segments and/or the segment length, that is, the angular expansion of the angular segments, is dependent upon operating parameters of the engine.

Detection of combustion misfiring

A method for detecting combustion misses in a multi-cylinder internal combustion engine. The control units of the engine use an engine control program which is interrupted by interrupt routines, in phase-synchronism with the rotational movement of the crankshaft, in which at least the data required for injection and firing are processed. The detection of combustion misses includes establishing and evaluating crankshaft segment times in which the crankshaft covers an associated circle-segment angle range. The crankshaft segment are also established and evaluated in particular interrupt routines, and for the further subset of cylinders in the interrupt routines in which their firing is controlled. Furthermore, the crankshaft segment times for the first cylinder is established and evaluated in certain additionally generated interrupt routines.

Method for detecting misfiring in a multi-cylinder internal combustion engine

The method serves for input signal correction of a misfire detection function and for cylinder equalization in an internal combustion engine, especially of a motor vehicle. Here, it is provided that a control for the input signal correction ( ) and a control of the cylinder equalization ( ) are activated alternatively by an alternative circuit unit ( ).

Method for correcting the input signal and for synchronizing the cylinders in an internal combustion engine

A method for detecting combustion misfires for internal combustion engines is introduced wherein an index for the rough running of the engine is formed and is compared to a threshold value. The threshold value is dependent upon the load of the engine. Exceeding the threshold value is evaluated as a misfire. The method is characterized in that the threshold value, in addition to being dependent upon the load, is also dependent upon the ignition angle and/or the lambda value or that the formation of the index for the rough running also takes place in dependence upon the ignition angle and/or on the lambda value; and/or that the activation/deactivation of the misfire detection is at least dependent upon the ignition angle and/or on the lambda value.

Method for detecting combustion misses

The invention relates to a method for detecting combustion misfires in a multi-cylinder internal combustion engine. Combustion misfires are detected from data for the rough running of individual cylinders via a comparison with threshold values at operating points stored in a characteristic field. These data are determined within the engine. The combustion misfire detection is suppressed below an rpm-dependent zero-load characteristic line. The zero-load characteristic line is continuously adapted to the actually present lowest load at corresponding rpm values during vehicle operation.

Method for detecting combustion misfires in a multi-cylinder internal combustion engine

The invention relates to a method for combustion misfire detection in multi-cylinder internal combustion engines. In the method, rough-running values for each cylinder of the engine are determined individually for each crankshaft rotation by measuring the segment times. The segment times include the times corresponding to the piston movement of each cylinder to be measured during which times the crankshaft passes through a corresponding circular segment angular region and, on the basis of filtered rough-running values, equalization or corrective factors are computed for each cylinder in an evaluation unit for influencing injection times or injection time points of each individual cylinder. The determined rough-running values (LUT) or the filtered rough-running values (FLUT) are compared in a desired value comparison to a threshold value (SW ) which is pregiven in value significantly less than the threshold value (SW ) for misfire detection. A reduction of the threshold value (SW ) for misfire detection to a lower level is effected by the continuous dropping below the second threshold value (SW ) within a pregiven time interval (&Dgr;t) or during a specific number of engine revolutions (&Dgr;u).

Method for detecting combustion misfires in an internal combustion engine

An arrangement includes a first controller which is only switched through to an actuator for a turbocharger if a fault recognition device detects no fault in the operation of the engine. A switchover is made from the first controller to a second controller, if the fault recognition device detects a critical fault. In this connection, the second controller receives a system deviation as an input signal that is different from the one received by the first controller. Thus in the event of a fault, the turbocharger can be controlled in a very flexible manner without the danger that the speed of the turbocharger is increased into its critical range.

Device for controlling boost pressure in an internal combustion engine

A separate irregular-running determination is carried out for each cylinder bank. Each ascertained irregular-running value is compared to a lower and an upper threshold value, the upper threshold value being set in such a way that all irregular-running values below it are not caused by combustion misses. A defect is signaled in one of the exhaust trains when, for at least one of the two cylinder banks, an irregular-running value is ascertained lying between the lower and the upper threshold value, and the difference between the irregular-running values of the two cylinder banks exceeds a threshold. This method makes it possible to ascertain a defect in one of the two cylinder banks very early.

Method and device for monitoring the functioning of two exhaust-gas turbochargers

The invention is directed to a method for high-resolution rpm detection in a multicylinder internal combustion engine having a crankshaft. Segment times (ts) are detected in which the crankshaft of the engine passes through predetermined angular regions. First corrective values are formed during overrun operation and logically coupled to the segment times (ts) so that deviations of the segment times (ts) of different segments are compensated in the overrun operation. Second corrective values outside of the overrun operation are determined on the basis of the corrected segment times and logically coupled to at least one of the corrected segment times and further processed segment times so that the deviations of the corrected segment times or the further processed segment times are compensated with each other during misfire-free operation.

Method for detecting RPM especially for detecting combustion misfires

The invention is directed to a method for detecting combustion misfires on the basis of a first input feature signal in which the nonuniformity of the rotational movement (on the basis of rpm or segment times) of the engine is mapped within the first order. According to the method, a permanent misfire at a cylinder is preliminarily detected when a first threshold value is exceeded by the amount of a first input feature signal and a detection signal for permanent misfires at several cylinders is active (and in this way, permanent misfires at several cylinders are recognized) when a threshold value is exceeded by the magnitude of further assigned input feature signals or by the magnitude of the first feature signal when a second threshold value is exceeded. The detection signal for permanent misfires at a cylinder is always switched to be inactive when there is an active detection signal for permanent misfire at several cylinders. When there is an inactive detection signal for permanent misfire at several cylinders, the preliminary detection signal for the permanent misfire at a cylinder becomes finally active and permanent misfires at a cylinder are recognized.

Method for detecting combustion misfires at one or more permanently

Method of detecting combustion misfires by evaluating RPM fluctuations

The invention is directed to a method for detecting combustion misfires on the basis of a first complex input feature signal wherein the nonuniformity of the rotational movement (on the basis of rpm or segment times) of the internal combustion engine is mapped within a first order defined by a rotation of the crankshaft through an angle of 720.degree./k wherein k=1. The input feature signal serves as a feature signal to detect recurring misfires and functions as a feature signal to detect sporadic misfires. The complex input signal is defined by a magnitude and a phase angle which vary as a function of time. The presence of a misfire is detected from the magnitude and the affected cylinder is determined from the phase angle.

Method for detecting combustion misfires via a separate classification

The invention is directed to a method for detecting combustion misfires in an internal combustion engine on the basis of a first signal wherein the nonuniformity of the rotational movement of the crankshaft of the engine is imaged. The method includes the steps of: generating a second signal which is periodic and has a period duration corresponding to one of the following: the cycle duration of a complete work cycle of the engine or the cycle duration divided by a whole number, and the second signal having a fixed phase relationship to the rotational movement of said crankshaft; providing an ancillary signal based on the first signal; modulating the second signal with the ancillary signal and filtering the second signal to form a third signal; and, utilizing the third signal for detecting the presence of misfires and for identifying the cylinder affected by the misfires.

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Stuttgart, Germany

Andrea Lohmann