DE102008043165B4 - Method and device for calibrating the pre-injection quantity of an internal combustion engine, in particular a motor vehicle - Google Patents

Abstract

Method for calibrating the injection quantity of at least one partial injection (300) provided in addition to a main injection (310) in an injection system (30) of an internal combustion engine (10), in particular of a motor vehicle, characterized in that a correction value (415) for a partial injection (300) in an individual cylinder of the internal combustion engine is determined by stimulating an injection pattern and by changing a speed oscillation caused by the injection pattern in the internal combustion engine (10), the control duration of at least one partial injection being varied until the effect on certain, preferably empirically predeterminable frequencies of a speed signal is minimized or regulated to zero.

Description

State of the art

The invention relates to a method for calibrating the injection quantity of a partial injection in an injection system of an internal combustion engine, in particular a motor vehicle, and a corresponding device according to the preambles of the respective independent claims.

The DE 10 2004 052 429 A1 discloses an injection quantity control device for accurately performing an injection quantity learning process on a diesel engine ( 1 ) creates an environment for obtaining a characteristic value in a one-to-one relationship with an actual injection quantity. A control device ( 11 ) performs a one-shot injection operation (S30) for a cylinder of the engine ( 1 ) while the environment is set up. An injection command amount is corrected based on an engine speed change caused by the one-shot injection operation. After setting the condition and before injecting, the opening of the valve ( 9 ) controlled so that it is smaller than a reference, and an opening of a diesel throttle ( 6 ) and a variable turbocharger ( 5 ) are controlled so that they are larger than a reference. A composition of an air flow into a combustion chamber ( 3rd ) is stabilized to ensure that the characteristic value that is detected after the one-shot injection operation is in a one-to-one relationship with the actual injection quantity.

In modern fuel injection systems, in particular self-igniting internal combustion engines, the fuel quantities injected into the combustion chambers by means of injectors are divided into several partial injections, which are arranged close in time and consist, for example, of one or more pre-injection (s) applied before a main injection. The time interval between two partial injections is defined by the pause time between two successive electrical control pulses of the injectors, by a crankshaft angle or by a combination of these two quantities.

These partial injections result in improved mixture preparation and thus lower exhaust gas emissions from the internal combustion engine, reduced noise during combustion and increased mechanical power output by the internal combustion engine. For the simultaneous optimization of noise and exhaust gas, the injection quantity of the pre-injection is selected to be very small, in some cases close to the smallest fuel quantity that can be represented by an injector.

In order to be able to guarantee the exact maintenance of the pre-injection quantity in the event of a drift of the injector behavior over the running time of the injector, functions are necessary which enable the pre-injection quantities to be calibrated while the internal combustion engine is still in operation. So it goes from DE 103 43 759 A1 discloses a method in which, when an internal combustion engine is idling, a pre-injection in one or more cylinders is switched off and the pre-injection quantity is deduced from the manipulated quantities of an idle regulator and a quantity compensation regulator on the basis of cylinder-specific corrections.

Disclosure of the invention

The present invention is based on the idea of determining a correction value for the partial injection into a single cylinder by stimulating an injection pattern and by changing or regulating a speed oscillation of the internal combustion engine (BKM) caused by the injection pattern in a calibration method concerned here.

In a preferred embodiment, a control algorithm is provided, which “rearranges” a pre-injection quantity between the pre-injection and the main injection for a cylinder with half, third, quarter, fifth, etc. camshaft frequency. I.e. It is proposed to alternately apply a single injection and a multiple injection, preferably a double injection composed of a pre-injection VE and a main injection HE, to a cylinder and a correction value for the pre-injection or partial injection by changing or regulating a speed oscillation of the BKM caused by the injection pattern to investigate.

The activation duration of a partial injection, preferably a pre-injection, is preferably varied in the aforementioned method until the effect on certain, preferably empirically predeterminable, frequencies of a speed signal is minimized or regulated to zero.

It should be emphasized that the mentioned speed oscillation can be detected not only by means of a speed signal but also on the basis of other input variables familiar to the person skilled in the art, such as a lambda signal, a knock signal, an ion current signal or the like.

The invention is based in particular on the knowledge that in the case of a preinjection quantity which has not yet been calibrated or has been only incompletely, vibrations with half, three half, etc. Camshaft frequency of the speed signal occur, which can preferably be adjusted to a minimum value by means of a control.

The aforementioned minimization of the speed oscillations is preferably carried out either on the basis of the amplitude and / or the phase position of the mentioned speed oscillations, or on the basis of a combination of these two variables, and is preferably determined by the amount and phase of a speed information item transformed into the frequency range.

In a preferred embodiment, two work phases are formed, namely a learning phase and a subsequent application phase. In the learning phase, a correction value of a cylinder is first determined by the stimulation of an injection pattern and by regulating the speed oscillation caused by the injection pattern. On the basis of the correction value determined in this way, the determined correction value is controlled in the subsequent application phase, preferably in normal operation of the internal combustion engine, to a currently available control variable of the pilot injection.

The method according to the invention enables precise calibration of the pre-injection quantity in the fired operation of an internal combustion engine or in the running operation of an underlying motor vehicle, and not necessarily in idle or in stationary operation of the internal combustion engine.

Since a cylinder compensation function is not required in the proposed method, the method can be used advantageously in engines with an unequal firing interval and in single-cylinder engines.

Compared to the method described in the introduction, the approach according to the invention does not require an overrun operation or even a stationary idle operation of the internal combustion engine. It should be emphasized here that in the methods known in the prior art, the load torque must not change during a calibration in idle operation, since this falsifies the calibration result. The known calibration methods can therefore only be carried out with the necessary precision in workshop operation. A quantity compensation control is also no longer required for the correction of the pre-injection quantity to be achieved. The calibration according to the known methods can be perceived acoustically, especially when idling, and therefore leads to a loss of comfort in the operation of the internal combustion engine.

In addition, the mentioned overrun operation cannot be applied in all applications of diesel engines, e.g. B. occurs in the off-road area, stationary engines or automatic transmissions, or only very rarely overrun. In addition, the aforementioned quantity compensation regulations according to the current state of the art are only possible for engines with the same ignition intervals, especially not for single-cylinder engines.

Figure list

The invention is explained in more detail below on the basis of preferred exemplary embodiments and with reference to the drawing, from which further special features, features and advantages of the invention emerge.

• 1 eine schematische Darstellung eines Kraftstoffzumesssystems einer Brennkraftmaschine gemäß dem Stand der Technik, bei dem die vorliegende Erfindung eingesetzt werden kann;
• 2 eine detaillierte Darstellung der an sich bekannten Berechnung von Ansteuerdauern eines in der 1 gezeigten elektrisch betätigten Ventils;
• 3 einen typischen Einspritzverlauf mit einer Vor- und Haupteinspritzung, anhand dessen die erfindungsgemäße Umlagerung der Einspritzmenge zwischen Vor- und Haupteinspritzung illustriert wird;
• 4 ein bevorzugtes Ausführungsbeispiel einer erfindungsgemäßen Korrekturfunktion anhand eines Blockdiagramms; und
• 5 ein an einem realen Kraftstoffzumesssystem in der erfindungsgemäßen Lemphase gemessenes Übertragungsverhalten.

Show in detail

• 1 is a schematic representation of a fuel metering system of an internal combustion engine according to the prior art, in which the present invention can be used;
• 2nd a detailed representation of the known calculation of control periods one in the 1 electrically operated valve shown;
• 3rd a typical injection course with a pre and main injection, on the basis of which the rearrangement of the injection quantity between the pre and main injection is illustrated;
• 4th a preferred embodiment of a correction function according to the invention using a block diagram; and
• 5 a transmission behavior measured on a real fuel metering system in the learning phase according to the invention.

Description of exemplary embodiments

The 1 shows a block diagram of the essential elements of a fuel metering system of an internal combustion engine. The internal combustion engine 10th received from a fuel metering unit 30th a certain amount of fuel metered at a certain point in time. Different sensors 40 record measured values 15 that characterize the operating state of the internal combustion engine and route it to a control unit 20 . The control unit 20 are also different output signals 25th other sensors 45 forwarded. The recorded measured values 15 characterize the state of the fuel metering unit, such as the driver's request. The control unit 20 calculated from these measurements 15 and the other sizes 25th Control pulses 35 with which the fuel metering unit 30th is applied.

The internal combustion engine is preferably a direct injection and / or a self-igniting internal combustion engine. The fuel metering unit 30th can be designed differently. For example, a distributor pump can be used as the fuel metering unit, in which a solenoid valve determines the time and / or the duration of the fuel injection.

Furthermore, the fuel metering unit can be designed as a common rail system. As is known, a high-pressure pump compresses fuel in a reservoir. The fuel then reaches the combustion chambers of the internal combustion engine via injectors from this store. The duration and / or the start of the fuel injection is controlled by means of the injectors. The injectors preferably include a solenoid valve or a piezoelectric actuator.

The control unit 20 calculates the amount of fuel to be injected into the internal combustion engine in a manner known per se. This calculation is based on various measured values 15 , such as the speed n, the engine temperature, the actual start of injection and possibly other variables 25th that characterize the operating state of the vehicle. These further variables are, for example, the position of the accelerator pedal or the pressure and the temperature of the ambient air. The control unit 20 then converts the desired amount of fuel into corresponding control pulses of the injectors.

In the case of the internal combustion engines mentioned, one or more small amounts of fuel are frequently metered into the cylinder shortly before the actual main injection. This can significantly improve the noise behavior of the engine. This injection is referred to as pre-injection and the actual injection as main injection. Furthermore, it can be provided that one or more small amounts of fuel (s) are metered after the main injection. This is then called post-injection. Furthermore, it can be provided that the individual injections are divided into further partial injections.

The problem with such fuel metering systems is that the electrically operated valves can meter different amounts of fuel with the same control signal. In particular, the actuation period at which fuel is being metered in depends on various factors. This minimum activation period leads to an injection, whereas activation periods shorter than the minimum activation period do not lead to an injection. This minimum activation period depends on various factors, such as temperature, fuel type, service life, rail pressure, manufacturing tolerances of the injectors and other factors. In order to achieve an accurate fuel metering, this minimum activation period must be known.

A device for controlling the fuel metering in an internal combustion engine is in the 2nd shown. Already in 1 elements described are designated by corresponding reference numerals. Signals from the sensors 45 and other sensors, which are not shown, arrive at a quantity specification 110 . This quantity specification 110 calculates a fuel quantity QKW that corresponds to the driver's request. This quantity signal QKW arrives at a connection point 115 , at its second input the output signal QKM of a second synchronization 155 is present. The output signal of the first node 115 reaches a second connection point 130 , which in turn is a trigger duration calculation 140 acted upon. At the second input of the second connection point 130 is the signal QKO of a zero quantity correction 142 on.

In the two connection points 115 and 130 the quantity signals are preferably linked additively. The actuation duration calculation 140 calculated from the output signal of the node 130 the control signal to act on a fuel metering unit 30th . The actuation duration calculation calculates the actuation duration with which the electrically operated valves are acted upon.

On a donor wheel 120 are different marks arranged by a sensor 125 be scanned. In the exemplary embodiment shown, the transmitter wheel is a so-called segment wheel which has a number of markings corresponding to the number of cylinders, in the exemplary embodiment shown there are four. This sensor wheel is preferably arranged on a crankshaft of the internal combustion engine, not shown. This means that a number of pulses is generated per engine revolution that corresponds to twice the number of cylinders. The sensor 125 delivers a corresponding number of pulses to a first synchronization 150 .

The first synchronization 150 applies a first controller 171 , a second controller 172 , a third regulator 173 and a fourth controller 174 . The number of controllers corresponds to the number of cylinders. The output signals of the four controllers then arrive at the second synchronization mentioned 155 .

Such a facility without zero quantity correction 142 is in the DE 195 27 218 A1 presented in more detail. This Establishment works as follows. The quantity specification determines the starting point on the basis of various signals, such as a signal that identifies the driver's request 110 the fuel quantity request signal QKW, which is required to provide the torque desired by the driver. In addition to the driver request signal, other signals can also be processed. In particular, in addition to the driver request signal, the speed signal and various temperature and pressure values are also processed. Furthermore, there is the possibility that other control units transmit signals to the quantity specification that request a torque request and / or a quantity request. Such a further control device can, for. B. be a transmission control that influences the torque from the engine during the switching process.

Due to tolerances, especially the fuel metering unit 30th deviations arise between the desired injection quantity and the actually injected fuel quantity. The individual cylinders of the internal combustion engine generally measure different amounts of fuel with the same control signal.

These variations between the individual cylinders are usually corrected using a quantity compensation regulation (MAR). Such a quantity compensation scheme is shown schematically in the upper part of the 2nd shown. A controller is assigned to each cylinder of the internal combustion engine to regulate the quantity balance. So the first cylinder is the first regulator 171 , the second cylinder the second regulator 172 , the third cylinder the third regulator 173 and the fourth cylinder is the fourth regulator 174 assigned. It can also be provided that only one controller is provided, which is alternately assigned to the individual cylinders. By means of the sensor 125 and the encoder wheel 120 determines the first synchronization 150 a setpoint and an actual value for each individual controller. It is provided that a special filtering of the signal of the sensor to compensate for tolerances of the sensor wheel and to compensate for torsional vibrations 125 he follows. The controller output signals 171 to 174 be a second synchronization 155 supplied, which provides a correction quantity QKM with which the quantity request QKW is corrected.

This quantity compensation regulation is designed in such a way that the regulators regulate the quantity allocated to the individual cylinders to a common mean value. If a cylinder measures an increased amount of fuel due to tolerances, a negative amount of fuel QKM is added to the driver's desired amount QKW for this cylinder. If a cylinder measures too little fuel, a positive amount of fuel QKM is added to the driver's desired amount QKW. With such quantity errors, rotational irregularity occurs. This has the effect that vibrations are superimposed on the speed signal, the frequency of which corresponds to the camshaft frequency and / or multiples of the camshaft frequency. These components in the speed signal with camshaft frequency characterize the rotational irregularity and are corrected to zero by the quantity compensation control.

Quantity average errors cannot be corrected with this quantity compensation scheme. In particular, errors which are based on the fact that no fuel is metered in below the minimum actuation duration mentioned cannot be corrected with such a quantity compensation regulation.

In the 3rd a typical injection pattern, consisting of a pre-injection and a main injection, is now shown schematically. The upper diagram shows the control of an injector, whereby the current control is neglected. The lower diagram shows the time-delayed fuel flow through the injector nozzle resulting from the aforementioned control. The areas under the respective curves of the fuel flow correspond to the amount of fuel injected.

• - „Lernmodus“: Ermitteln des Korrekturwerts durch Stimulation des Einspritzmusters und Ausregeln der Drehzahlschwingung
• - „Anwendungsmodus“: Aufsteuern des ermittelten Korrekturwerts im normalen Motorbetrieb

The calibration method according to the invention now has the two working phases or operating modes already mentioned:

• - "Learning mode": determining the correction value by stimulating the injection pattern and regulating the speed oscillation
• - "Application mode": control of the determined correction value in normal engine operation

In the “learning” mode, the method according to the invention rearranges the pre-injection quantity between the pre-injection and the main injection, preferably cyclically, for one cylinder and, for example, at half the camshaft frequency. Such a rearrangement cycle is preferably repeated more than once, but in the simplest case can only be carried out by a single cycle, i.e. a single redistribution can be realized, since a single cycle is capable of causing a speed oscillation.

It should be emphasized that the injection pattern described here for the rearrangement of a pre-injection with respect to a main injection is only exemplary and in principle other injection patterns are also conceivable by means of which a speed oscillation can be excited. Instead of a pre-injection, a post-injection can be rearranged accordingly or an even more complex "rearrangement pattern" in which more than one partial injection is rearranged.

In the in the 3rd Embodiment shown is the amount of fuel provided for the pre-injection 300 alternately as the amount of fuel 305 to the main injection 310 steered on. However, it goes without saying that other forms of rearrangement are also possible, such as, for example, the rearrangement of the fuel quantity of a pre-injection with a post-injection that is separate in time from the main injection.

The present invention is based on the finding that only in cases in which the fuel quantities physically deposited during the cyclical rearrangement 300 , 305 are the same, no speed vibration occurs. As already with the 1 described, it can happen that the electrically operated valves of the injectors measure different amounts of fuel with the same control signal. Therefore, if the control duration is the same, it is not automatically guaranteed that the two fuel quantities 300 and 305 to match. The force offsets are also for drifted injectors or for a calibration process that has not been learned 300 , 305 naturally unequal and the speed fluctuations described above occur. The aim of the calibration process is therefore to regulate these speed fluctuations to a minimum or to detect the phase jump. The manipulated variable for this is a corrective action on the activation duration of the pilot injection 300 .

It goes without saying that the concept according to the invention is not only applicable to the calibration of pre-injections, but also to the calibration of partial injections which are carried out in addition to a main injection, for example also to post-injections or the like.

Based on the in the 4th shown block diagram of a preferred device according to the invention, preferred interventions of the calibration method according to the invention in the engine control are described in greater detail.

Starting from a moment path 400 A setpoint torque m is specified, which represents a setpoint of the internal torque on the motor from the coordination of the driver specification, speed controller, etc. This target torque m is first of all by means of a torque quantity conversion 405 converted into a setpoint of the pre-injection quantity qVEsoll and a main injection quantity qHEsoll.

In a logically or procedurally subsequent quantity control duration conversion 410 the input quantities of the pre-injection with impressed stimulation in half the camshaft frequency qVEstim and a corresponding value qHEstim for the main injection are available at their input, which are determined by a correction function ZFX described below 430 to be provided.

The specified quantity control duration conversion 410 calculates from the values qVEstim and qHEstim values of the control duration for the pre-injection tiVE and the main injection tiHE, without the correction / calibration function according to the invention. On the injectors shown only schematically 415 there is then a value tiVEcorr for the control duration of the pre-injection including a corresponding control intervention of a calibration function and a control duration value tiHE for the main injection. By means of the injectors 415 these control values are converted into actual values qVEphys for the pre-injection quantity injected and qHEphys for the main injection quantity to be injected. Based on these actual values, the motor, which is also only indicated schematically, generates 420 in operation in a manner known per se, a rotary movement of its (not shown) crankshaft at a specific speed n.

Using a spectral analysis 425 the amplitude and / or the phase of the resulting speed oscillation are evaluated at half the camshaft frequency, and alternatively also at frequencies other than the basic frequency of the oscillation. The sequence control of the subsequent correction function ZFX 430 calculates a logic signal stVEstim to stimulate the injection pattern with half the camshaft frequency and from the phase and / or the amplitude an intervention tiVEtrim of the correction function ZFX, ie a corresponding intervention to compensate for the assumed injector drift.

The Indian 4th The process shown also contains logical links in the form of a first link point 435 and a second node 440 and a first switch 445 and a second switch 450 . It should be noted that in the present exemplary embodiment the first switch 445 rather works in the form of a switch and either the lower path 455 switches to continuity or the upper path 460 .

By means of the first connection point 435 the specified setpoint of the pre-injection quantity qVEsoll can be increased to the specified setpoint of the main injection quantity qHEsoll. Whether this activation takes place or not depends on the switch position of the first switch 445 from. Using the second switch 450 however, will controls whether the setpoint of the pre-injection quantity qVEsoll is processed further in the form of a separate pre-injection, ie the pre-injection quantity is then not controlled to the setpoint of the main injection quantity qHEsoll. In the embodiment shown, the two switches work 445 , 450 thus in opposite directions, ie when the first switch 445 opens, the second switch closes 450 , and vice versa.

The switch positions of the two switches are controlled by the correction function ZFX by means of the mentioned logic signal stVEstim, whereby in one cycle (i.e. with half the camshaft frequency) - as described above - the pre-injection takes place separately from the main injection, i.e. the pilot injection quantity is not added to the main injection quantity, and in the subsequent cycle the pilot injection is represented in the form of an extended main injection, i.e. the pre-injection quantity is added to the main injection quantity.

At the second connection point, said control intervention tiVEtrim and the present value of the actuation duration for the pilot injection tiVE are added in order to result in the corrected value tiVEcorr for the actuation duration of the pilot injection for the respective injector (s).

In the 5a - 5c is the transmission behavior in the "Learn" mode from tiVEtrim to amplitude ( 5a) and phase ( 5b) the speed vibration with half the camshaft frequency shown on the basis of a measurement. In particular, these figures illustrate the behavior of amplitude and phase of 0.5 * f _NW when the trigger duration trim on the pilot injection changes. The value of the control intervention, which results in an amplitude = 0 or a minimal amplitude, is in the 3rd shown fuel quantities 300 and 305 equal. Beyond the minimum, the amplitude increases again. The phase information of the oscillation is used to distinguish whether too large or too small an amount is injected on the cylinder, ie to identify the control sense.

erfüllt ist.The intervention tiVEtrim when the speed oscillation disappears (ie amplitude = 0) represents the correction value at which the equation $$\text{qVEsoll}=\text{qVEphys}$$

is satisfied.

This correction value tiVEtrim ( 5c ) is saved, possibly depending on other engine parameters such as rail pressure. In the "Apply" work phase, the correction value appropriate for the engine operating state is opened again. Optionally, the correction value used can also be determined from several learning values of neighboring operating points.

As an alternative to the regulation described, the oscillation amplitude of the speed n at half the camshaft frequency can also be used as a measure of the pre-injection quantity. In order to be robust to changes in the route behavior with this solution, a route identification can be preceded by a quantity variation of the skin injection. As an alternative to the control described, other dividers of the camshaft frequency can also be excited in addition to ½: B. 1/3 camshaft frequency by varying two camshaft revolutions with pre-injection and one camshaft revolution without pre-injection, ¼ camshaft frequency etc. For the evaluation of the speed oscillation, the selected excitation frequency and / or its multiples are also used here. As an alternative to the described evaluation of the speed oscillation at half the camshaft frequency, integer multiples of the excitation frequency can additionally or alternatively be used to determine the amplitude and phase. A route identification as mentioned above can also be used to learn the phase for the later calibration procedure on controlled systems with oscillating components. As an alternative to the correction intervention on the activation duration of the pilot injection described in the invention, a correction to the target quantity of the pilot injection can also take place.

In contrast to the known methods, the pre-injection is not permanently stopped or switched off during calibration, but is alternately stimulated on a cylinder. In one work cycle of the cylinder to be calibrated, the normal injection pattern consisting of pre-injection and main injection is discontinued. In the subsequent work cycle, the pilot injection is switched off and the pilot injection quantity is added to the main injection. As a result, if there is an error in the pre-injection quantity, a speed oscillation with half the camshaft frequency (and harmonics) is excited. The resulting speed oscillation is analyzed and corrected by intervening in the control duration of the injector. The correction intervention is a measure of the calibration value of the injector.

Further resulting advantages over the known methods are the robustness against changes in the average load torque, since in the preferred exemplary embodiment described only an analysis takes place at half the camshaft frequency and a correlation is made between a change in the quantity of the main injection and the pre-injection quantity. This is possible under the condition that the change in the injector slope δm / δ drive duration for the main injection is small over the service life. Robustness in relation to different drive trains is thereby achieved, since the calibration can be carried out in a closed control loop. Thanks to the robust, calibration-based calibration method, the effort for the application of the function is lower than with the previously known speed-based methods. Due to the fact that it is largely independent of the drive train, no different data is to be expected in the case of drive train configuration variants. Furthermore, there is no influence of cylinder-specific disturbances or pitch errors of the speed sensor wheel, since these cannot occur at half the camshaft frequency. In addition, calibration is also possible in an operating range in which the driver is insensitive to changes in the combustion noise. Finally, calibration can be carried out in wide speed and load ranges with the rail pressures specified for these operating points, or in a limited interval around the specified rail pressure. It is not necessary to set special rail pressures for calibration, which would not be optimal for this operating point and lead to the noise development mentioned.

Claims (13)

Method for calibrating the injection quantity of at least one partial injection (300) provided in addition to a main injection (310) in an injection system (30) of an internal combustion engine (10), in particular a motor vehicle, characterized in that a correction value (415) for a partial injection (300) in a single cylinder of the internal combustion engine is determined by stimulating an injection pattern and by changing a speed oscillation in the internal combustion engine (10) caused by the injection pattern, the activation duration of at least one partial injection being varied until the effect on certain, preferably empirically predeterminable, frequencies of a speed signal is minimized or regulated to zero. Procedure according to Claim 1 , characterized in that the amplitude of the speed vibration is minimized or corrected to a minimum. Procedure according to Claim 1 , characterized in that a change in the phase of the speed oscillation, in particular a phase jump, is taken as a basis. Method according to one of the preceding claims, characterized in that for the individual cylinder with a fraction of the camshaft frequency, preferably with a camshaft frequency (1 / n), where n = 2, 3, 4, ..., a predetermined injection quantity of a partial injection (300) between a pre-injection or a post-injection and a main injection (310). Method according to one of the preceding claims, characterized in that said change in the speed oscillation takes place on the basis of the amplitude or the phase position of the speed oscillation or on the basis of a combination of these two variables (420, 425). Method according to one of the preceding claims, characterized in that the calibration takes place in at least two working phases, a correction value of a cylinder being determined in the first working phase by said stimulation of an injection pattern and by said changing of the speed oscillation caused by the injection pattern, and wherein in In the second working phase, the correction value determined in this way during operation of the internal combustion engine is controlled to a currently available control variable of the pilot injection. Method according to one of the preceding claims, characterized in that an effect on the speed oscillation is determined by the amount and / or phase of speed information transformed into the frequency range. Method according to one of the preceding claims, characterized in that the amplitude and / or the phase of the speed oscillation is evaluated by means of spectral analysis (425), at least the fundamental frequency of the speed oscillation being taken into account. Procedure according to Claim 8 , characterized in that the spectral analysis (425) evaluates at least one other frequency than the fundamental frequency of the speed oscillation. Method according to one of the preceding claims, characterized in that a logic signal for stimulating the injection pattern is generated from the amplitude of the speed oscillation and an actuating intervention is generated (430) from the phase of the speed oscillation. Device for calibrating the injection quantity of a partial injection (300) provided in addition to a main injection (310) in an injection system (30) of an internal combustion engine (10), in particular a motor vehicle, characterized by computing means or control means (430) for determining a correction value for a partial injection (300 ) in a single cylinder Internal combustion engine (10) on the basis of a stimulation of an injection pattern and the changing of a speed oscillation caused by the injection pattern in the internal combustion engine, the control duration of at least one partial injection being varied until the effect on certain, preferably empirically predetermined frequencies of a speed signal is minimized or increased Is regulated zero. Device after Claim 11 , characterized by a controller for regulating the speed vibration to a minimum. Device after Claim 11 or 12th , characterized by a logic unit (430) for calculating a logic signal for stimulating the injection pattern from the amplitude of the speed oscillation and for generating an intervention from the phase of the speed oscillation.

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