DE102016219067A1 - Method for operating an internal combustion engine - Google Patents

Abstract

The invention relates to a method for operating an internal combustion engine (100) having at least one combustion chamber (105) in which by means of one or more of the at least one combustion chamber (105) corresponding, fuel injectors (130) fuel from a high pressure accumulator (120) in the at least one combustion chamber (105) is injected, wherein for at least one injection of fuel, a deviation of a characteristic of the at least one injection fuel quantity is determined by a corresponding setpoint, and based on the determined deviation of the at least one combustion chamber ( 105), the oxygen or air quantity to be supplied to the internal combustion engine is adapted to the quantity of fuel injected during the at least one injection.

Description

The present invention relates to a method for operating an internal combustion engine as well as a computer unit and a computer program for its implementation.

State of the art

In current injection systems, both for gasoline and for diesel, the amount of fuel delivered (injected quantity) during injection processes by means of fuel injectors correlates very well with the duration of injection, ie with the opening duration of the nozzle or injection valve of the fuel injector, if the injection pressure is known. A regulation of this opening duration to a set value predetermined by, for example, a motor control can therefore lead to a considerable increase in the metering accuracy.

The prerequisite for such a control is usually a correct detection of the injection or opening duration or at least the end of injection with respect to the start of control. These are for example from the DE 10 2014 209 330 A1 , of the DE 10 2009 002 483 A1 or the DE 10 2010 000 827 A1 different concepts known.

A basic concept for the control of the opening duration or at least the time interval between control start and end of injection is for example in the DE 10 2009 002 593 A1 shown. In this and similar systems, the opening duration of the nozzle or the injection valve of the fuel injector can be detected and adjusted by tracking the driving time to a desired value.

Disclosure of the invention

According to the invention, a method for operating an internal combustion engine as well as a computing unit and a computer program for carrying it out with the features of the independent patent claims are proposed. Advantageous embodiments are the subject of the dependent claims and the following description.

A method according to the invention serves to operate an internal combustion engine having at least one combustion chamber, in which fuel is injected from a high-pressure accumulator into the at least one combustion chamber by means of one or more fuel injectors corresponding to the at least one combustion chamber. In addition to internal combustion engines with only one combustion chamber and those with two, three, four, five, six, eight, ten, twelve or even a different number of combustion chambers are conceivable. In this case, for at least one injection of fuel (as a rule all injections or at least main injections per operating cycle of the internal combustion engine are considered) a deviation of a variable characteristic of the quantity of fuel injected in the at least one injection from a corresponding desired value is determined. Based on the determined deviation, an oxygen or air quantity to be supplied to the at least one combustion chamber of the internal combustion engine is then adapted to the quantity of fuel injected during the at least one injection.

In other words, a deviation of the fuel quantity injected in one or more injection processes into the corresponding combustion chambers is thus initially determined by a desired fuel quantity to be injected. For this purpose, it should be noted that the injected fuel quantity can be determined from an associated opening duration of the respective fuel injectors (taking into account the fuel pressure and the flow through the fuel injector). The relevant deviation can therefore be determined both on the basis of the opening duration and on the basis of the injected fuel quantity (in the sense of the mentioned characteristic variable). In this case, in turn opening times and / or activation periods and / or control start and / or drive ends and / or opening times and / or closing times of the fuel injectors used can also be used.

Instead of adjusting the injected fuel quantity (or the opening duration) based on the determined deviation, the quantity of oxygen or air to be supplied to the combustion chamber (s) is adjusted. By adapting the amount of oxygen or air to the determined fuel quantity, an adaptation of the (stoichiometric) ratio between the injected fuel quantity and the amount of oxygen required for optimal combustion (or alternatively the corresponding air quantity) should be understood. In particular, the injection quantity or opening duration is therefore not adapted, at least not on average over all the fuel injectors used. An adaptation of the individual fuel injectors with respect to the determined characteristic value (in the sense of a so-called quantity equalization), however, is conceivable and often also advantageous, since non-uniformities in the torque can be compensated.

The amount of oxygen or air to be supplied can be adjusted in particular by adjusting an exhaust gas recirculation rate and / or a boost pressure and / or a throttle position. Thus, the necessary ratio can be set very quickly and effectively. A Verification of the ratio or a determination of the necessary adjustment of the oxygen or air quantity can also be made using a hot-film air mass meter (or a comparable device) and / or a lambda probe with which the ratio between fuel and air or Oxygen can be detected.

In the from the DE 10 2009 002 593 A1 known methods, an injection quantity for fuel injectors can be regulated to a certain value. In addition, it is also possible, for example, to keep the injection quantity constant over the service life, taking account of coking or other flow-changing degradation in the fuel injectors.

Such systems show their advantages especially in full-load operation of the internal combustion engine and at very small injection quantities. At full load, an injection duration control - possibly in conjunction with the aforementioned coking correction - keeps both the injection quantity and the end of injection within narrow limits and also changes only slightly over the service life. As a result, safety provisions, for example to protect a turbocharger against excessive exhaust gas temperatures, can be significantly reduced so that the internal combustion engine can be better utilized than with an unregulated system.

In this case, small injection quantities usually have special functions, for example as pre- and post-injections in a diesel engine, in order to condition the combustion chamber or reduce the raw emission of particles or in the case of a gasoline engine for rapid heating of the three-way catalyst. These injections are therefore usually not torque-forming, but fulfill emission-relevant special functions. Therefore, there are also increased demands on their metering accuracy in such injections, which can be met by an adaptation or control system.

In the case of mainly torque-forming injections, in particular in the partial load range, the situation is different. Here, the control and also a control of the injection amount by the driver of a corresponding motor vehicle itself, as this usually does not specify an accelerator pedal position, but this the desired Acceleration adapts and automatically compensates for quantity deviations of the injection system. In these driving conditions, regulation of the injection duration and thus of the injection quantity can even be counterproductive.

During operation of the motor vehicle or the internal combustion engine, the injection scenario may change in different driving situations, for example by switching off a pre-injection or the like. This can lead to an injection quantity jump due to inaccuracies in the feedforward control, for example to an additional amount. This in turn leads to a slight torque jump, which the driver can perceive.

Now, as a rule, two different reactions take place. First, the driver will take gas to compensate for the increased torque. On the other hand, however, at the same time recognizes the control system, as mentioned above, this excess quantity on the basis of the delayed compared to the setpoint injection end and regulates by returning the control period of the fuel injectors this again to the desired value. This leads to a rapid decrease of the momentarily excessive torque, but at the same time also the target torque is reduced by the driver reaction. Overall, this leads to an unnecessarily large torque jump downwards, which the driver can perceive as an even stronger jerk and which he in turn will compensate by actuating the gas pedal. In particular, this second jerk, which is only caused by adjusting the amount of fuel to its desired value, is often perceived by the driver as particularly disturbing.

In the proposed method, however, only the amount of oxygen or air is now adapted to a changed fuel or injection quantity, so that the emission values are kept as low as when adjusting the amount of fuel to a desired value. An adjustment of the amount of fuel itself is not made, but the driver himself will correct such a Zumessfehler (by instinct) by appropriate operation or withdrawal of the accelerator pedal and perceived by the driver as unpleasant second jerk by adjusting the fuel quantity to its desired value remains off.

Preferably, the quantity characteristic of the quantity of fuel injected in the at least one injection comprises a characteristic opening duration for the fuel injectors used in the at least one injection (this may, for example, be an average of the opening durations of the fuel injectors used). The corresponding desired value then includes a characteristic opening duration characteristic of the fuel injectors used in the at least one injection, so that the two values can be compared with one another and the deviation can be determined. It is understood that the deviation is then a period of time. As a rule, time durations are determined in each case for the individual fuel injectors, one for the injected fuel quantity to obtain characteristic size, so no further conversion is necessary. It is understood, however, that an averaging of the fuel injectors used can be made.

It is also particularly expedient if the characteristic opening duration characteristic of the fuel injectors used in the at least one injection is determined from a characteristic desired fuel quantity to be injected in the at least one injection. This characteristic setpoint fuel quantity may be, for example, a setpoint fuel or injection quantity that is common or else specified separately for all fuel injectors. The desired opening duration can be calculated from the desired fuel quantity, taking into account the injection pressure and possibly the flow rate of the fuel injectors.

In this way, a very simple determination of the deviation is possible, from which in turn the corresponding adjustment of the oxygen or air quantity can be determined. Here is then possibly also a conversion of the time available as a deviation in a fuel quantity required in order to obtain the necessary amount of oxygen or air.

It is also preferred if the quantity characteristic of the quantity of fuel injected in the at least one injection comprises a characteristic amount of fuel injected by the fuel injectors used in the at least one injection. The corresponding desired value then includes a characteristic desired fuel quantity to be injected in the case of the at least one injection. It is understood that the deviation is then an amount of fuel. In this case, no conversion is necessary for the setpoint, but for the characteristic size. Thus, however, a simple calculation of the deviation is also possible here.

For the conversion of the usually first determined time duration for the fuel injectors used or individual injections in a corresponding amount of fuel (as already mentioned above, taking into account the injection pressure and possibly the flow rate) there are various preferred options.

For this, in multiple injections, the characteristic amount of fuel injected by the fuel injectors used may be determined across a plurality of fuel injectors to form an average of an injected fuel amount and / or a sum of injected fuel amount for each of a plurality of fuel injectors over multiple injections of a respective fuel injector. In other words, therefore, the conversion can be made only if a, for example, average, opening duration has been determined for all fuel injectors or injections, but the conversion can already be done separately for each fuel injector, so that then, for example, a fuel quantity and no longer an opening period is averaged over the fuel injectors used. Depending on the type of injection and possibly existing conversion errors, another type of calculation may be more advantageous or more accurate.

It is also advantageous if the quantity characteristic of the quantity of fuel injected during the at least one injection is determined for a plurality of injections per fuel injector and operating cycle of the internal combustion engine taking into account all or only selected injections per fuel injector and duty cycle. In this way, for example, pre-injections or post-injections can continue to be corrected in the usual way, as mentioned at the outset, since these are generally not torque-forming, but may be relevant for the emission values. If these are then regulated back to their nominal value, they do not have to be taken into account when adjusting the oxygen or air volume.

Preferably, a flow-varying degradation occurring in the case of the fuel injectors used for the at least one injection, in particular coking, is taken into account in determining the deviation. This can be done in particular by taking into account the flow-changing degradation in the determination of the characteristic size. Here, again, the flow-changing degradation can be taken into account, in particular, by adjusting an opening period for fuel injectors used in the at least one injection separately or comprehensively and / or separately or comprehensively for each of the at least one injection. Thus, it may be considered that, for example, a reduced flow rate requires a longer opening time for the same amount of fuel to be injected. This correction can be carried out at various points, similar to the conversion from the opening duration to the fuel quantity, ie, for example directly for a fuel injector or an injection, but also only after averaging over all fuel injectors or accumulation of individual injections. This makes it possible to achieve the most accurate adaptation of the amount of oxygen or air over the life of the fuel injectors.

Furthermore, it is also preferable if the flow-changing degradation is taken into account in the determination of the characteristic variable by adjusting separately or across and / or separately for each of the fuel injectors used fuel injected at least one injection and / or for each of the at least one injection. This means that not only the opening period, but also the amount of fuel, which is usually first determined from the opening period, can be corrected accordingly. Depending on the type of injections or possibly existing conversion errors, one or the other type can be more accurate.

Alternatively or additionally, it is also preferred if the flow-changing degradation is taken into account by an adaptation of the desired value, in particular by a characteristic target opening duration for fuel injectors used in the at least one injection separately or across and / or for each of the at least one injection separately or across is adjusted. In other words, not only can the determined, actual values that are characteristic of the injected fuel quantity be corrected, but also the setpoint values can be corrected accordingly. This is possible as well as possible an exact adaptation over the lifetime of the fuel injectors.

An arithmetic unit according to the invention, e.g. a control device of a motor vehicle is, in particular programmatically, configured to perform a method according to the invention.

Also, the implementation of the method in the form of a computer program is advantageous because this causes very low costs, especially if an executive controller is still used for other tasks and therefore already exists. Suitable data carriers for providing the computer program are in particular magnetic, optical and electrical memories, such as e.g. Hard drives, flash memory, EEPROMs, DVDs, etc. It is also possible to download a program via computer networks (Internet, intranet, etc.).

Further advantages and embodiments of the invention will become apparent from the description and the accompanying drawings.

The invention is illustrated schematically by means of embodiments in the drawing and will be described below with reference to the drawing.

Brief description of the drawings

1 schematically shows an internal combustion engine with common rail system, which is suitable for carrying out a method according to the invention.

2 to 5 schematically show processes of a method according to the invention in various preferred embodiments, in particular with regard to the determination of the deviation by means of the characteristic size.

6 to 9 schematically show processes of a method according to the invention in various preferred embodiments, in particular with regard to a correction due to flow-changing degradation.

Embodiment (s) of the invention

In 1 is schematically an internal combustion engine 100 shown, which is suitable for carrying out a method according to the invention. By way of example, the internal combustion engine comprises 100 three combustion chambers or associated cylinders 105 , Every combustion chamber 105 is a fuel injector 130 assigned, which in turn each to a high-pressure accumulator 120 , a so-called rail, via which it is supplied with fuel. It goes without saying that a method according to the invention can also be carried out in an internal combustion engine with any other number of cylinders, for example one, two, four, five, six, eight, ten or twelve cylinders.

Next is the high-pressure accumulator 120 via a high-pressure pump 110 with fuel from a fuel tank 140 fed. The high pressure pump 110 is with the internal combustion engine 100 coupled, for example, such that the high-pressure pump is driven via a crankshaft of the internal combustion engine, or via a camshaft, which in turn is coupled to the crankshaft.

A control of the fuel injectors 130 for metering or injecting fuel into the respective combustion chambers 105 via a motor control unit 180 trained computing unit. For the sake of clarity, only the connection from the engine control unit 180 to a fuel injector 130 However, it is understood that each fuel injector 130 is connected to the engine control unit accordingly. Every fuel injector 130 can be specifically controlled. Furthermore, the engine control unit 130 adapted to the fuel pressure in the high-pressure accumulator 120 by means of a pressure sensor 190 capture.

In the 2 to 5 are schematic processes of inventive method in various preferred embodiments and in particular with regard to the determination of the deviation by means of the characteristic size.

In 2 For example, use of an opening period as a characteristic amount for injections is shown. For this purpose, an opening duration of the respective fuel injector for the respective injection is initially determined for each fuel injector (three by way of example here) and there for each individual injection (three by way of example here, which can be divided in particular into a pre, a main and a post injection). By way of example, the opening times T _1,1 , T _1,2 and T _1,3 are shown here only for the first fuel injector.

For determining the opening duration in an injection, for example, an injection end can be measured based on the start of control. If the start of injection is known, the injection duration or opening duration can then be calculated by subtraction. In this case, a delay of the start of injection compared to the start of control can be measured directly, but it can also be calculated offline from different parameters and taken into account.

If there is no information about this delay individually for each fuel injector, it can also be used as a substitute value, a known, uniform delay of a medium fuel injector at the present pressure in the high-pressure accumulator or injection pressure. It is also conceivable that this substitute value is set to zero for the sake of simplicity.

From the opening durations T _1,1 , T _1,2 and T _1,3 for the individual injections of the first fuel injector, an entire opening duration T _{1 of} the first fuel injector can now be determined, for example, by summing up. Accordingly, such opening periods T ₂ and T _{3 can} also be formed for the other fuel injectors.

The summation and the averaging can also be carried out in a common calculation step. It goes without saying that the step of totaling is omitted if there is only one injection per fuel injector and operating cycle of the internal combustion engine, or if, as already mentioned, the pre-injection and the post-injection remain unconsidered. It goes without saying that only individual injections can be disregarded.

Subsequently, from these opening periods T ₁ , T ₂ and T _{3 of} the individual fuel injectors, an average opening duration T _M can be determined as the characteristic variable for the injected fuel quantity. This mean opening duration T _M may, for example, be the arithmetic mean value of the opening durations T ₁ , T ₂ and T ₃ .

Furthermore, from a for the injection injections, characteristic target fuel amount, here a mean per Kraftstoffinjektor to be injected target fuel quantity Q _target , a corresponding target opening time T _Soll (here, a mean target opening period), taking into account the pressure in the high-pressure accumulator or injection pressure p are determined.

Further, a deviation .DELTA.T is now (that is, a period of time here) of the central opening period T _M is determined from the target opening period T _set. Based on the deviation ΔT, the amount of oxygen or air to be supplied in the (in particular following) injections can then be adapted to the actually injected fuel quantity. For this purpose, the divergence present as time duration can initially be converted into a fuel quantity taking into account the injection pressure p.

This can be achieved, for example, by correcting the exhaust gas recirculation rate R _A (here individually for the combustion chambers) and / or the boost pressure p _L (here for a total amount of air to be supplied) and / or a throttle position D (also for a total amount of air to be supplied). As a result, the required ratio of fuel and oxygen mass is maintained regardless of an injection quantity error, and the quantity error does not result in an increase in exhaust emissions.

In particular, this deviation .DELTA.T is not corrected by a control intervention with, for example, a control variable of the control period, but converted into an additionally required or excessively present amount of oxygen.

The desired oxygen mass flow or the resulting desired fresh air mass flow can be measured by a so-called air mass meter (hot-film air mass meter, HFM) and adjusted to the setpoint value corrected by the measured actual opening or injection duration or the actual injection quantity. Optionally, a lambda probe can be used, via which the actual lambda value can be measured, which describes the relationship between oxygen and fuel mass in the combustion chamber.

Since this lambda value should have a known, well-defined value for air mass flow adjusted in the correct proportion to the injected fuel quantity, the lambda probe can additionally be used for calibrating the hot-film air mass meter over its service life become. Deviations of the lambda value from its nominal value indicate a measurement deviation of the hot-film air mass meter, which can then be corrected. In this way, a diagnosis of the hot-film air mass meter can be made. If the measurement error is too great, this can be detected and the driver can be advised to replace the hot-film air mass meter.

At the in 3 In the embodiment shown, a mean injected fuel quantity Q _{M is} used as the characteristic variable whose deviation ΔQ is determined from the desired fuel quantity Q _Soll . In this case, no conversion of the desired fuel quantity into a desired opening duration is required, however, a conversion of the average opening duration T _M into the average fuel quantity Q _{M is} undertaken. In this case, the injection pressure p can be taken into account.

The average opening duration T _M can be determined in the same way as in relation to 2 was described in more detail. Based on the deviation ΔQ, the oxygen or air quantity can then be adjusted. Compared to the embodiment according to 2 in this case, no conversion of the desired fuel quantity into a mean nominal opening duration T _setpoint is necessary.

In the 4 embodiment shown basically corresponds to that according to 3 However, the conversion from an opening period into a fuel quantity does not take place after the averaging over all fuel injectors, but already individually for each fuel injector, but after the summation of the individual injections per fuel injector and duty cycle. Accordingly, an averaging of the individual fuel quantities Q ₁ , Q ₂ and Q _{3 is then} necessary in order to obtain the average fuel quantity Q _M.

In the 5 embodiment shown basically corresponds to that according to 4 However, the conversion from an opening period into a fuel quantity does not take place after the summation of the individual injections per fuel injector and duty cycle, but before the summation and then individually according to each individual injection.

Accordingly, the fuel quantities Q _1,1 , Q _1,2 and Q _1,3 are then added up to the fuel quantity Q ₁ (and correspondingly to the other fuel injectors). From the fuel quantities Q ₁ , Q ₂ and Q ₃ , an average value is then formed in order to obtain the mean fuel quantity Q _M.

In the 6 to 9 schematically processes of inventive method are shown in various preferred embodiments and in particular with regard to a correction due to flow-changing degradation, in this case in particular a coking.

In the in 6 In embodiments shown, the flow-varying degradation (coking) is taken into account as the characteristic variable in determining an opening duration.

If a coking recognition (detection of a flow change of the nozzle injection holes of the fuel injectors) is provided, then the cylinder-specific coking degrees or the coking degree averaged over the internal combustion engine can be taken into account in different ways.

Since the amount of fuel or injection quantity associated with a given opening period or injection duration is smaller with a coked nozzle than with uncoked nozzle, the measured opening duration can be reduced depending on the degree of coking. Only then follow the further processing and the comparison with a corresponding desired opening duration or the conversion into a fuel quantity and the comparison with a desired fuel quantity.

As shown in the picture above, an opening period can first be determined or measured for each individual injection per fuel injector and duty cycle, but - in the case of coking - it is longer than usual. Here, this raw opening time for the first injection of the first injector is denoted by T ' _1,1 .

Taking into account the injection pressure p, an effect factor K can now be determined, which can be dependent on the injection duration and / or the injected fuel quantity and indicates the effect of the coking per se on the opening duration. This effect factor is between zero and one, but can generally be approximated as one.

This effect factor K is then multiplied by an injector-specific degree of coking k ₁ (here for the first fuel injector) and then subtracted from one (1). In this way, one obtains a proportion which indicates the change in the opening duration of the coked fuel injector with respect to a corresponding opening duration of the uncoupled force injector, in each case with the same injection quantity.

By multiplying so the actual injected fuel quantity corresponding opening duration T _1.1 an uncoked fuel injector can be determined. This is necessary to avoid any coking effects when compared with the target Opening period, which is usually applicable to unfiltered fuel injectors to take into account.

The embodiment shown in the middle figure corresponds basically to that in the upper picture, but with the difference that the correction is not made for the opening duration of each injection per injector and duty cycle, but after their summation, which here with the opening times T ' ₁ and T ₁ for the first fuel injector is shown.

The embodiment shown in the lower picture basically corresponds to that in the middle image, but with the difference that the correction is made not only after the summation, but also after the averaging over all fuel injectors, which here with the average opening times T ' _M and T _{M is} shown.

Furthermore, it is not an injector-individual degree of coking that is used, but rather a typical or a mean coking degree k _M for the entire internal combustion engine. This procedure is useful, for example, if only one such medium degree of coking is present. However, it can also be determined from the individual coking levels.

In the 7 Embodiments shown basically correspond to those according to 6 , but with the difference that not the opening times are corrected based on the Verkokungsgraden, but the corresponding amounts of fuel. To convert it to the 3 to 6 and the corresponding description.

In the in 8th In embodiments shown, the flow-changing degradation (coking) is taken into account at the target opening duration. Since the opening duration associated with an injection quantity or quantity of fuel is greater with a coked nozzle than with an uncorrected nozzle, the setpoint value for the opening duration can also be increased as a function of the coking.

The calculation basically corresponds to that according to 6 , but with the difference that the raw target opening duration T ' _target , as it would actually be used, is first divided by the corresponding proportion, so that the further target opening duration T _{target is} correspondingly greater. Here is - unlike 6 - A division (by a factor less than one) instead of a multiplication necessary to adjust the target opening duration to the extended actually necessary opening duration.

In this case, an injector-individual correction (upper image), then with the injector-specific degree of coking k ₁ (here for the first fuel injector) and for an injector-individual desired opening duration T _{Soll, 1} or a uniform for all fuel injectors correction (lower image), then with the average coking degree k _M and for a mean target opening duration T _{Soll be} made.

Furthermore, as in 9 shown, an injector-individual correction (upper image), then with the injector-individual coking k ₁ (here for the first fuel injector) and for a injector-individual target opening duration T _{Soll, 1,1} per single injection per cycle (here for the first fuel injector and its first injection) or a uniform correction for all fuel injectors (lower image), then with the average degree of coking k _M and for a mean target opening time T _{Soll, n, 1} (here for the first injection per work cycle, shown for an n-th Fuel injector) per single injection per cycle.

QUOTES INCLUDE IN THE DESCRIPTION

This list of the documents listed by the applicant has been generated automatically and is included solely for the better information of the reader. The list is not part of the German patent or utility model application. The DPMA assumes no liability for any errors or omissions.

Cited patent literature

• DE 102014209330 A1 [0003]
• DE 102009002483 A1 [0003]
• DE 102010000827 A1 [0003]
• DE 102009002593 A1 [0004, 0010]

Claims (16)

Method for operating an internal combustion engine ( 100 ) with at least one combustion chamber ( 105 ), in which by means of one or more, this at least one combustion chamber ( 105 ) correspondingly assigned, fuel injectors ( 130 ) Fuel from a high pressure accumulator ( 120 ) into the at least one combustion chamber ( 105 ), wherein for at least one injection of fuel a deviation (ΔT, ΔQ) of a variable (T _M , Q _M ) characteristic of the quantity of fuel injected in the at least one injection from a corresponding desired value (T _target , Q _target ) is determined, and wherein based on the determined deviation (.DELTA.T, .DELTA.Q) one of the at least one combustion chamber ( 105 ) the oxygen or air quantity to be supplied to the internal combustion engine is adapted to the quantity of fuel injected in the at least one injection. Method according to claim 1, wherein said at least one combustion chamber ( 105 ) to be supplied oxygen or air amount is adjusted by an exhaust gas recirculation rate (R _A ) and / or a boost pressure (p _L ) and / or a throttle position (D) are adjusted. Method according to claim 1 or 2, wherein the characteristic quantity (T _M , Q _M ) characteristic of the quantity of fuel injected during the at least one injection takes into account opening times (T _1,1 , T _1,2 , T _1,3 , T ₁ , T ₂ , T ₃ ) and / or drive durations and / or drive start and / or drive ends and / or opening times and / or closing times of respective fuel injectors used in the at least one injection ( 130 ) is determined. Method according to one of the preceding claims, wherein the characteristic of the injected at least one injection amount of fuel characteristic size characteristic of the fuel injectors used in the at least one injection opening period (T _M ) and the corresponding setpoint one for the fuel injectors used in the at least one injection characteristic set opening duration (T _setpoint ), and wherein in particular the fuel injectors used for the at least one injection ( 130 ) characteristic target opening duration (T _setpoint ) is determined from a characteristic setpoint fuel quantity (Q _setpoint ) to be injected during the at least one injection. Method according to one of the preceding claims, wherein the quantity characteristic of the quantity of fuel injected in the at least one injection is a fuel injector used in the at least one injection ( 130 ) injected, characteristic fuel quantity (Q _M ) and the corresponding desired value to be injected in the at least one injection, characteristic target fuel quantity (Q _Soll ). Method according to Claim 5, in which, for several injections, the fuel injectors used by the injectors ( 130 ) injected characteristic quantity of fuel (Q _M ) to form an average value of an injected fuel quantity over a plurality of fuel injectors ( 130 ) and / or determining a sum of injected fuel quantity for each of a plurality of fuel injectors across a plurality of injections of a respective fuel injector. Method according to one of the preceding claims, wherein the quantity characteristic of the quantity of fuel injected in the at least one injection is variable in the case of several injections per fuel injector and operating cycle of the internal combustion engine ( 100 ) taking into account all or only selected injections per fuel injector ( 130 ) and duty cycle is determined. Method according to one of the preceding claims, wherein one of the fuel injectors used for the at least one injection ( 130 ) occurring flow-changing degradation in the determination of the deviation is taken into account. Method according to claim 8, wherein the flow-changing degradation is taken into account in the determination of the quantity (T _M , Q _M ) which is characteristic of the quantity of fuel injected in the at least one injection. The method of claim 9, wherein the flow-varying degradation is taken into account in the determination of the characteristic size by adjusting an opening period for fuel injectors used in the at least one injection separately or across and / or for each of the at least one injection separately or across. Method according to claim 9 or 10, wherein the flow-changing degradation in the determination of the characteristic variable (Q _M ) is taken into account by separately injecting an amount of fuel injected during the at least one injection for the fuel injectors used separately and / or separately for each of the at least one injection or overriding. Method according to one of claims 8 to 11, wherein the flow-changing degradation is taken into account by an adaptation of the desired value (T _Soll , Q _Soll ), in particular by a characteristic target opening duration for the fuel injectors used at least one injection ( 130 ) is adapted separately or across and / or for each of the at least one injection separately or across. Method according to one of the preceding claims, wherein, based on the determined deviation (ΔT, ΔQ), the quantity (T _M , Q _M ) characteristic of the quantity of fuel injected during the at least one injection is determined individually for a plurality of fuel injectors ( 130 ) is adjusted in the direction of the determined characteristic variable. Arithmetic unit ( 180 ), which is adapted to perform a method according to any one of the preceding claims. Computer program comprising a computing unit ( 180 ) to perform a method according to any one of claims 1 to 13, when it on the computing unit ( 180 ) is performed. A machine-readable storage medium having a computer program stored thereon according to claim 15.

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