Method and control device for operating an internal combustion engine

Abstract

Method for operating an internal combustion engine, wherein, in order to influence fuel combustion in cylinders of the internal combustion engine, a cylinder-specific fuel injection quantity (12) for the fuel to be burned in the respective cylinder is specified for each cylinder as a cylinder-specific manipulated variable, in such a way that a pilot control value (10) for the fuel injection quantity that is common to all cylinders of the internal combustion engine is specified, wherein the cylinder-specific fuel injection quantity (12) is determined from the pilot control value (10) for the fuel injection quantity that is common to all cylinders for each cylinder in such a way that a cylinder-specific combustion load is equated with or approximated to the fuel combustion in the cylinders of the internal combustion engine.

Description

[0001] The invention relates to a method and a control device for operating an internal combustion engine.

[0002] The present invention relates in particular to the field of so-called large engines or large internal combustion engines, whose cylinders have piston diameters of at least 140 mm, in particular of at least 175 mm. Such large internal combustion engines include, for example, marine engines.

[0003] In an internal combustion engine, a relatively unignitable fuel can be burned as fuel, which is then ignited, for example, via an ignition device such as a spark plug or alternatively via an ignition fuel, also referred to as pilot fuel. The present invention relates to a method and a control unit for operating an internal combustion engine in which a relatively unignitable fuel is burned as fuel, which is then ignited either via an ignition device or via a pilot fuel.

[0004] Methods and control units for operating such an internal combustion engine are already known in practice. Control variables are specified for the operation of the internal combustion engine. For example, one control variable is a fuel injection quantity for the fuel to be burned in the cylinders. Another control variable is at least one ignition parameter, which serves to ignite the fuel to be burned in the cylinders. Such an ignition parameter can be, for example, the quantity of pilot fuel, the number and duration of individual pilot fuel injections, or the timing and energy for an ignition device.

[0005] DE 10 2014 005 986 A1 discloses a method for operating an internal combustion engine according to the preamble of claims 1, 3 and 10, respectively.

[0006] DE 10 2006 049 264 A1, DE 10 2006 021 090 B3 and EP 2 698 521 A1 and disclose further prior art.

[0007] There is a need to operate an internal combustion engine even more efficiently. Based on this, the invention is based on the object of creating a novel method and control unit for operating an internal combustion engine, with the aid of which internal combustion engines can be operated even more efficiently.

[0008] This object is achieved according to a first aspect of the invention by a method according to claim 1. According to claim 1d, a pilot control value for the fuel injection quantity that is common to all cylinders of the internal combustion engine is specified, wherein the cylinder-specific fuel injection quantity is determined from the pilot control value for the fuel injection quantity that is common to all cylinders for each cylinder as a first manipulated variable in such a way that a cylinder-specific combustion load is equated with or approximated to the fuel combustion in the cylinders of the internal combustion engine.According to claim 1, a cylinder-specific setpoint value for a cylinder-specific combustion load controller is determined for the respective cylinder as a function of a knocking frequency of the respective cylinder and / or as a function of a peak pressure exceedance frequency or intermediate pressure exceedance frequency of the respective cylinder, which outputs a cylinder-specific offset value as an output variable, the individual fuel injection quantity being determined from the pilot control value for the fuel injection quantity common to all cylinders and the cylinder-specific offset values for each cylinder.

[0009] According to a second aspect of the invention, this object is achieved by a method according to claim 3. According to claim 3, a pilot control value for the respective ignition parameter that is common to all cylinders of the internal combustion engine is specified, wherein the respective cylinder-specific ignition parameter is determined from the pilot control value for the respective ignition parameter that is common to all cylinders for each cylinder in such a way that a cylinder-specific combustion position in the cylinders of the internal combustion engine is equalized or approximated. Preferably, an adapted pilot control value for the respective ignition parameter that is common to all cylinders is first determined from the pilot control value for the respective ignition parameter that is common to all cylinders for all cylinders in such a way that an average value of a combustion position of the fuel combustion in all cylinders of the internal combustion engine corresponds to a specified target value, wherein the pilot control value for the respective ignition parameter that is common to all cylindersadapted pilot control value for the respective ignition parameter for each cylinder, the respective cylinder-specific ignition parameter is determined in such a way that the cylinder-specific combustion position in the cylinders of the internal combustion engine is equalized or approximated. According to claim 3, furthermore, from the pilot control value for the respective ignition parameter common to all cylinders, an adapted pilot control value for the respective ignition parameter common to all cylinders is first determined in such a way that an average value of a combustion position of the fuel combustion in all cylinders of the internal combustion engine corresponds to a predetermined target value, wherein the respective cylinder-specific ignition parameter is determined for each cylinder from the adapted pilot control value for the respective ignition parameter common to all cylinders in such a way that the cylinder-specific combustion position in the cylinders of the internal combustion engine is equalized or approximated,and wherein the adapted pilot control value common to all cylinders for the respective ignition parameter is determined in such a way that, depending on a knocking frequency of all cylinders and / or depending on a peak pressure exceedance frequency or intermediate pressure exceedance frequency of all cylinders, a setpoint value is determined for a combustion position controller common to all cylinders, which outputs a common offset value for the respective ignition parameter as an output variable, wherein the adapted pilot control value common to all cylinders for the respective ignition parameter is determined from the pilot control value common to all cylinders for the respective ignition parameter and the offset value common to all cylinders for the respective ignition parameter.

[0010] According to a third aspect of the invention, this object is achieved by a method according to claim 10. According to claim 10, a pilot control value for the fuel injection quantity that is common to all cylinders of the internal combustion engine is specified, wherein the cylinder-specific fuel injection quantity is determined from the pilot control value for the fuel injection quantity that is common to all cylinders for each cylinder as a first manipulated variable in such a way that a cylinder-specific combustion load is equated with or approximated to the fuel combustion in the cylinders of the internal combustion engine.Furthermore, according to the third aspect of the invention, a pilot control value for the respective ignition parameter that is common to all cylinders of the internal combustion engine is specified, wherein from the pilot control value for the respective ignition parameter that is common to all cylinders, an adapted pilot control value for the respective ignition parameter that is common to all cylinders is first determined in such a way that an average value of a combustion position of the fuel combustion in all cylinders of the internal combustion engine corresponds to a specified target value, and wherein from the adapted pilot control value for the respective ignition parameter that is common to all cylinders, the respective cylinder-specific ignition parameter is determined for each cylinder in such a way that a cylinder-specific combustion position in the cylinders of the internal combustion engine is equated or approximated.According to claim 10, a control value for a boost pressure control element of an exhaust gas turbocharger is further specified as a control variable for the operation of the internal combustion engine, such that a setpoint for a nitrogen oxide controller is determined depending on the knocking frequency of all cylinders and / or depending on the peak pressure exceedance frequency or intermediate pressure exceedance frequency of all cylinders, which outputs a setpoint for a boost pressure controller as an output variable, the boost pressure controller outputting the control value for the boost pressure control element as an output variable.

[0011] According to a fourth aspect of the invention, this object is achieved by a control device according to claim 12.

[0012] The invention enables efficient operation of an internal combustion engine. Individual control variables are determined for each cylinder from pilot control values common to all cylinders of the internal combustion engine. As the first cylinder-specific control variable, a cylinder-specific fuel injection quantity is determined for each cylinder in such a way that a cylinder-specific combustion load is equal to or approximated by the fuel combustion in the cylinders.

[0013] Alternatively or additionally, the respective cylinder-specific ignition parameter is determined as at least a second cylinder-specific manipulated variable for each cylinder in such a way that a cylinder-specific combustion position in the cylinders of the internal combustion engine is equalized or approximated.

[0014] The invention allows a particularly effective combustion of the fuel and thus a particularly efficient operation of an internal combustion engine is possible.

[0015] Preferably, the individual fuel injection quantity is determined for each cylinder from the pilot control value for the fuel injection quantity common to all cylinders as the first cylinder-specific control variable such that a mean combustion pressure or a peak combustion pressure in the cylinders is equalized or approximated as the combustion load. This is particularly preferred for determining the cylinder-specific control variables for the fuel injection quantity.

[0016] Preferably, the respective cylinder-specific ignition parameter is determined from the adapted pilot control value common to all cylinders for the respective ignition parameter as the respective second cylinder-specific manipulated variable for each cylinder in such a way that a defined combustion conversion point in the cylinders is equated or approximated as the combustion position. In particular, a 5% conversion point, a 30% conversion point, a 50% conversion point, or a 70% conversion point can be equated or approximated as the defined combustion conversion point. This is particularly preferred for determining the cylinder-specific manipulated variables for the respective ignition parameter.

[0017] Preferably, the adapted pilot control value common to all cylinders for the respective ignition parameter is determined in such a way that, depending on a knocking frequency of all cylinders and / or depending on a peak pressure exceedance frequency or intermediate pressure exceedance frequency of all cylinders, a setpoint value is determined for a combustion position controller common to all cylinders, which outputs the common offset value for the respective ignition parameter as an output variable, wherein the adapted pilot control value common to all cylinders for the respective ignition parameter is determined from the pilot control value common to all cylinders for the respective ignition parameter and the offset value common to all cylinders for the respective ignition parameter.Depending on the cylinder-specific knock frequency of the respective cylinder and / or depending on the cylinder-specific peak pressure exceedance frequency or intermediate pressure exceedance frequency of the respective cylinder, a cylinder-specific setpoint is determined for the respective cylinder for a cylinder-specific combustion position controller, which outputs a cylinder-specific offset value as an output variable. The respective cylinder-specific ignition parameter is determined as the respective second cylinder-specific manipulated variable for each cylinder from the adapted pilot control value common to all cylinders for the respective ignition parameter and the cylinder-specific offset values of the cylinder-specific combustion position controller. This can further improve the determination of the cylinder-specific manipulated variables for the respective ignition parameter.

[0018] Preferred developments of the invention will become apparent from the dependent claims and the following description. Exemplary embodiments of the invention are explained in more detail, without being limited thereto, with reference to the drawings. Herein: Fig. 1 is a block diagram illustrating a first aspect of the method according to the invention for operating an internal combustion engine, Fig. 2 a block diagram to illustrate a further development of the first aspect of the method according to the invention for operating an internal combustion engine, Fig. 3 is a block diagram illustrating a second aspect of the method according to the invention for operating an internal combustion engine, Fig. 4 a block diagram to illustrate a further development of the second aspect of the method according to the invention for operating an internal combustion engine.

[0019] The structure of an internal combustion engine is familiar to the person skilled in the art and requires no further explanation. For the sake of completeness, it should simply be pointed out that an internal combustion engine has several cylinders. Fuel is burned in the cylinders of an internal combustion engine. For this purpose, the fuel to be burned, along with charge air, is supplied to the cylinders. When the fuel is burned, exhaust gas is produced in the cylinders, which is then discharged from the cylinders of the internal combustion engine.

[0020] If an internal combustion engine is equipped with an exhaust gas turbocharger, the exhaust gas is fed into a turbine of the exhaust gas turbocharger, where it expands and generates mechanical energy. The generated mechanical energy is used to drive a compressor of the exhaust gas turbocharger, thus compressing the charge air supplied to the internal combustion engine, namely its cylinders.

[0021] In connection with the invention, it is to be assumed that a relatively unignitable fuel is burned in the cylinder of the internal combustion engine, which is then ignited either by means of an ignition fuel, also referred to as pilot fuel, or by means of an ignition device such as a spark plug.

[0022] In order to influence the combustion of the fuel in the cylinders of the internal combustion engine, at least two control variables are specified for each cylinder, namely a fuel injection quantity of the relatively unignitable fuel to be burned into the cylinder, and at least one ignition parameter for igniting the fuel to be burned in the cylinders.

[0023] In an internal combustion engine in which the unignitable fuel is ignited via a pilot fuel, at least one ignition parameter may be the quantity of pilot fuel introduced and the timing of the pilot fuel introduction. In an internal combustion engine that uses an ignition device such as a spark plug to ignite the fuel, the at least one ignition parameter may be the ignition timing and the ignition energy of the ignition device.

[0024] In order to operate an internal combustion engine, a pilot control value 10 common to all cylinders of the internal combustion engine (see Fig. 1, Fig. 2) for a fuel injection quantity.

[0025] This pilot control value 10 for the fuel injection quantity, which is common to all cylinders of the internal combustion engine, represents the amount of fuel that is relatively unignitable and must be ignited in the cylinders for combustion. This fuel, which is relatively unignitable and is ignited using an ignition fuel or an ignition device, is also referred to as the main fuel.

[0026] Alternatively or preferably additionally, at least one pilot control value 11 common to all cylinders of the internal combustion engine (see Fig. 3, Fig. 4) specified for at least one ignition parameter. A single pre-control value common to all cylinders can be specified for a single ignition parameter, but pre-control values can also be specified for multiple ignition parameters common to all cylinders of the internal combustion engine.

[0027] The pilot control value 10 for the fuel injection quantity of the main fuel, which is common to all cylinders of the internal combustion engine, is used as a cylinder-specific control variable 12 (see Fig. 1, Fig. 2) For each cylinder of the internal combustion engine, a cylinder-specific fuel injection quantity of the main fuel is determined. Accordingly, the cylinder-specific fuel injection quantity 12 is determined for each cylinder as a cylinder-specific control variable, depending on the pilot control value 10 for the fuel injection quantity common to all cylinders of the internal combustion engine.

[0028] Alternatively, or preferably additionally, at least one cylinder-specific ignition parameter 13 (see Fig. 3, Fig. 4). The cylinder-specific ignition parameters 13 are determined depending on the pilot control value 11 common to all cylinders for the respective ignition parameter. As already explained, a single cylinder-specific ignition parameter 13 can be determined for each cylinder; more than one cylinder-specific ignition parameter 13 can be determined for each cylinder.

[0029] The block diagram shows the further control variable Fig. 2, Fig. 4 a control value 14 for a boost pressure control element of an exhaust gas turbocharger. The boost pressure control element can, for example, be a so-called wastegate of an exhaust gas turbocharger of the internal combustion engine.

[0030] According to a first aspect of the invention (see Fig. 1, Fig. 2) From the pilot control value 10 common to all cylinders for the fuel injection quantity of the main fuel that is not ready to ignite and for the combustion of the same, the cylinder-specific fuel injection quantity 12 of the main fuel is determined as a first manipulated variable for each cylinder, as explained above, in such a way that a cylinder-specific combustion load is equated with or approximated to the fuel combustion in the cylinders of the internal combustion engine.

[0031] The combustion load is preferably defined as a mean pressure of combustion or a peak pressure of combustion in the cylinders of the internal combustion engine, or as being equal to or approximate to it. The mean pressure is preferably a so-called indicated mean pressure.

[0032] To determine the cylinder-individual fuel injection quantity 12, the invention uses a combustion load controller 15. The combustion load controller 15 regulates the combustion load for each cylinder individually, in particular either the mean pressure or the peak pressure.

[0033] For this purpose, a corresponding target value 17 is specified to the combustion load controller 15 for either the mean pressure or the peak pressure, whereby this target value 17 is essentially the same for all cylinders. However, a cylinder-specific offset 16 for this target value is specified to the combustion load controller 15 for each cylinder.

[0034] This cylinder-specific offset for the target value of the combustion load controller is determined individually in block 18 for each cylinder of the internal combustion engine, depending on a cylinder-specific knock frequency 19 of the respective cylinder and / or depending on a cylinder-specific peak pressure exceedance frequency 20 or alternatively cylinder-specific mean pressure exceedance frequency of the respective cylinder.

[0035] Depending on the cylinder-specific knock frequency 19 and / or the cylinder-specific peak pressure exceedance frequency 20 or, alternatively, the cylinder-specific intermediate pressure exceedance frequency of the respective cylinder, a cylinder-specific offset value 16 for the target value 17 of the cylinder-specific combustion load controller 15 is determined in block 18, which then outputs a cylinder-specific offset value as output variable 21, namely a cylinder-specific offset value 21 for the fuel injection quantity. The cylinder-specific fuel injection quantity 12, the respective first manipulated variable for each cylinder, is determined from the pilot control value 20 for the fuel injection quantity common to all cylinders and the cylinder-specific offset values 21.

[0036] According to a second aspect of the invention (see Fig. 3, Fig. 4) alternatively or preferably in addition to the first aspect of the invention, the respective cylinder-specific ignition parameter 13 is determined from the pilot control value 11 common to all cylinders for the respective ignition parameter for each cylinder in such a way that a cylinder-specific combustion position in the cylinders of the internal combustion engine is equalized or approximated.

[0037] In a further development of the second aspect of the invention, it is preferably provided that for the respective ignition parameter, an adaptive pre-control value 22 common to all cylinders of the internal combustion engine is first determined.

[0038] The adaptive pilot control value 22 common to all cylinders of the internal combustion engine is determined such that an average value of a combustion position of the fuel combustion in all cylinders of the internal combustion engine corresponds to a predetermined target value 23. Depending on a knock frequency 24 of all cylinders and / or depending on a peak pressure exceedance frequency or intermediate pressure exceedance frequency of all cylinders, an offset value 26 common to all cylinders for the target value 23 is determined in a block 27.

[0039] A combustion position controller 28 common to all cylinders of the internal combustion engine determines an offset value common to all cylinders for the pilot control value 11 of the respective ignition parameter common to all cylinders from the setpoint value common to all cylinders and the offset value common to all cylinders for the setpoint value as output variable 29, wherein the pilot control value 11 of the respective ignition parameter common to all cylinders is offset against the offset value 29 common to all cylinders in order to determine the adapted pilot control value 22 common to all cylinders.

[0040] From the adapted pre-control value 22 for the respective ignition parameter, which is common to all cylinders, the respective cylinder-specific ignition parameter is then determined for each cylinder as at least one second cylinder-specific manipulated variable 13, namely in such a way that a cylinder-specific combustion position in the cylinders of the internal combustion engine is equalized or approximated.

[0041] While the combustion position for all cylinders is controlled jointly in the combustion position controller 28, a combustion position control is carried out for each cylinder individually in a combustion controller 30, which outputs a cylinder-individual offset value for the respective ignition parameter as output variable 31.

[0042] In the second aspect of the invention, the combustion position controller 28 is optional but preferred. In the second aspect of the invention, the combustion position controller 30 is mandatory.

[0043] The adapted pilot control value 22 common to all cylinders is offset against the cylinder-specific offset values 31 in order to determine the cylinder-specific ignition parameter 13 as a further cylinder-specific manipulated variable 13 from the adapted pilot control value 22 common to all cylinders for the respective cylinder.

[0044] Then, if the combustion position controller 28 is not present, the pilot control value 11 common to all cylinders is offset against the cylinder-specific offset values 31 in order to determine the cylinder-specific ignition parameter 13 as a further cylinder-specific manipulated variable 13 from the adapted pilot control value 22 common to all cylinders for the respective cylinder.

[0045] The combustion position controller 30, which carries out the combustion position control for each cylinder individually, is supplied with a target value 32 for the combustion position of the respective cylinder as an input variable, on the one hand, and on the other hand, starting from the block 18 described above in connection with the first aspect of the invention, an offset value 33 for the target value 32 depending on the cylinder-specific knock frequency 19 of the respective cylinder and / or depending on the cylinder-specific peak pressure exceedance frequency 20 or alternatively the cylinder-specific intermediate pressure exceedance frequency of the respective cylinder.

[0046] In the combustion position controllers 28, 30, a defined combustion turnover point is preferably controlled as the combustion position.

[0047] This combustion conversion point can be a 5% conversion point, a 30% conversion point, a 50% conversion point, or a 70% conversion point, with the percentage indicating the fuel burned and thus converted at the respective conversion point. The 50% conversion point is also referred to as the combustion center.

[0048] The combustion position controller 28 is preferably a PI controller. The combustion load controller 15 and combustion position controller 30 are each preferably an I controller.

[0049] In blocks 18 and 27, the respective offset for the respective target value can be determined depending on the respective knock frequency and / or peak pressure exceedance frequency or intermediate pressure exceedance frequency depending on the characteristic map.

[0050] As already explained, the control variable for the operation of the internal combustion engine is preferably still a control value 14 (see Fig. 2, Fig. 4) for a boost pressure control element of an exhaust gas turbocharger.

[0051] This is preferably done in such a way that the block 27 outputs an offset value 35 for a target value 36 of the nitrogen oxide controller 34 depending on the knock frequency 24 of all cylinders and / or depending on the peak pressure exceedance frequency 25 or intermediate pressure exceedance frequency of all cylinders for a nitrogen oxide controller 34.

[0052] The nitrogen oxide controller 34 outputs a target value for a boost pressure controller 38 as output variable 37, which compares the target value 37 with an actual value 39 and, depending on the deviation, generates the manipulated variable 14 for the boost pressure control element.

[0053] In connection with the determination of the cylinder-specific ignition parameters 13, a common adaptation of the pilot control value 11 for all cylinders is preferably carried out via the combustion position controller 28 common to all cylinders in order to provide the adapted pilot control value 22 common to all cylinders for the respective ignition parameter. Subsequently, or even without the combustion position controller 28, an individual combustion position control is carried out for each cylinder in the combustion position controller 30 in order to provide the cylinder-specific ignition parameters 13, whereby the combustion position in the cylinders of the internal combustion engine is equalized or approximated.

[0054] It is also possible to compensate for cyclic fluctuations in the mean effective pressure or peak pressure in the cylinders, which depend on a variation coefficient, using the combustion position controller 30. This is done by adjusting the cylinder-specific manipulated variables 13 for the respective ignition parameter on a cylinder-by-cylinder basis. Instead of a mean effective pressure variation coefficient or a peak pressure variation coefficient, the incident mean effective pressure or peak pressure can also be used directly as an additional reference variable in block 30.

[0055] According to the second aspect of the invention, at least one cylinder-specific ignition parameter 13 is determined as the cylinder-specific manipulated variable for each cylinder. According to the first aspect of the invention, alternatively or in addition to the first aspect of the invention, the cylinder-specific fuel injection quantity 12 is determined as the cylinder-specific manipulated variable for each cylinder, specifically via the combustion load controller 15 in such a way that the mean pressure of combustion or the peak pressure of combustion is equated to or approximated as the combustion load. Particularly preferably, the cylinder-specific manipulated variable 12 and / or the cylinder-specific manipulated variable 13 are determined in conjunction with the determination of a manipulated variable 14 for a boost pressure control element.This manipulated variable 14 for the boost pressure control element is determined as a function of the nitrogen oxide controller 34 and boost pressure controller 38, preferably as a function of the knock frequency 24 of all cylinders and / or the peak pressure exceedance frequency 25 or intermediate pressure exceedance frequency of all cylinders.

[0056] In an advantageous further development of the invention, it can be provided that the combustion position controller 28 common to all cylinders is assigned a further Fig. 1 to provide an offset value for the target value 23. This additional offset value for the target value 23 can be determined depending on the fuel injection quantity of all cylinders in such a way that the efficiency of the internal combustion engine is approximated to a corresponding target value, in particular such that the internal combustion engine is operated with optimal efficiency. In this case, the combustion position, a cylinder pressure, or even an indicated mean effective pressure can also be taken into account.

[0057] The invention further relates to a control unit of an internal combustion engine, which is configured to automatically execute the method described above on the control side. This control unit is, in particular, an electronic engine control unit. List of reference symbols 10 Pre-control value for fuel injection quantity 11 Pre-control value for ignition parameters 12 cylinder-specific fuel injection quantity 13 cylinder-specific ignition parameters 14 Control value boost pressure control element 15 Combustion load controller 16 cylinder-specific offset 17 Target value 18 blocks 19 cylinder-specific knock frequency 20 cylinder-specific peak pressure exceedance frequency 21 Offset value 22 adapted input tax value 23 Target value 24 Knock frequency of all cylinders 25 Peak pressure exceedance frequency of all cylinders 26 Offset value 27 Block 28 Combustion position controllers of all cylinders 29 Offset value 30 cylinder-specific combustion position controllers 31 Offset value 32 Target value 33 Offset value 34 nitrogen oxide regulators 35 Offset value 36 Target value 37 Output size 38 boost pressure regulator 39 Actual value

Claims

[1] Method for operating an internal combustion engine, wherein, in order to influence fuel combustion in cylinders of the internal combustion engine, a cylinder-specific fuel injection quantity (12) for the fuel to be burned in the respective cylinder is specified for each cylinder as a cylinder-specific control variable, such that a pilot control value (10) common to all cylinders of the internal combustion engine is specified for the fuel injection quantity, from the pilot control value (10) for the fuel injection quantity common to all cylinders, the cylinder-specific fuel injection quantity (12) is determined for each cylinder in such a way that a cylinder-specific combustion load is equal to or approximated to the fuel combustion in the cylinders of the internal combustion engine, characterized by , that Depending on a knock frequency (19) of the respective cylinder and / or depending on a peak pressure exceedance frequency (20) or intermediate pressure exceedance frequency of the respective cylinder, a cylinder-specific setpoint value for a cylinder-specific combustion load controller (15) is determined for the respective cylinder, which outputs a cylinder-specific offset value (21) as an output variable, wherein the individual fuel injection quantity (12) is determined for each cylinder from the pilot control value (10) for the fuel injection quantity common to all cylinders and the cylinder-specific offset values (21). [2] Method according to claim 1, characterized bythat the individual fuel injection quantity (12) is determined for each cylinder from the pilot control value (10) for the fuel injection quantity common to all cylinders in such a way that a mean pressure of combustion or a peak pressure of combustion in the cylinders is equated or approximated as the combustion load. [3] Method for operating an internal combustion engine, in particular according to one of claims 1 or 2, wherein, in order to influence fuel combustion in cylinders of the internal combustion engine, at least one cylinder-specific ignition parameter (13) for igniting the fuel to be burned in the respective cylinder is specified as cylinder-specific control variables for each cylinder in such a way that a pilot control value (11) common to all cylinders of the internal combustion engine is specified for the respective ignition parameter, from the pilot control value (11) common to all cylinders for the respective ignition parameter, the respective cylinder-specific ignition parameter (13) is determined for each cylinder in such a way that a cylinder-specific combustion position in the cylinders of the internal combustion engine is equalized or approximated, characterized by , that from the pilot control value (11) common to all cylinders for the respective ignition parameter, an adapted pilot control value (22) common to all cylinders of the internal combustion engine for the respective ignition parameter is first determined in such a way that an average value of a combustion position of the fuel combustion in all cylinders of the internal combustion engine corresponds to a predetermined target value, from the adapted pre-control value (22) common to all cylinders for the respective ignition parameter, the respective cylinder-specific ignition parameter (13) is determined for each cylinder in such a way that the cylinder-specific combustion position in the cylinders of the internal combustion engine is equalized or approximated, the adapted pilot control value (22) common to all cylinders for the respective ignition parameter is determined in such a way that, depending on a knock frequency (24) of all cylinders and / or depending on a peak pressure exceedance frequency (25) or intermediate pressure exceedance frequency of all cylinders, a setpoint value for a combustion position controller (28) common to all cylinders is determined, which outputs a common offset value (29) for the respective ignition parameter as an output variable, wherein the adapted pilot control value (22) common to all cylinders for the respective ignition parameter is determined from the pilot control value (11) common to all cylinders for the respective ignition parameter and the offset value (19) common to all cylinders for the respective ignition parameter. [4] Method according to claim 3, characterized bythat the respective cylinder-individual ignition parameter (13) is determined from the adapted pre-control value (22) common to all cylinders for the respective ignition parameter for each cylinder as a manipulated variable in such a way that a defined conversion point of the combustion in the cylinders is equated or approximated as the combustion position. [5] Method according to claim 4, characterized by that the defined combustion conversion point is equal to or approximated to a 5% or 30% or 50% or 70% conversion point. [6] Method according to one of claims 3 to 5, characterized bythat the adapted pilot control value (22) common to all cylinders for the respective ignition parameter is further determined in such a way that, depending on the pilot control value (10) common to all cylinders for the fuel injection quantity, the setpoint value for the combustion position controller (28) common to all cylinders is adapted in such a way that an efficiency wheel of the internal combustion engine is brought closer to a corresponding setpoint value. [7] Method according to claim 2 and according to claim 3 or claim 6, characterized bythat, depending on the knock frequency (19) of the respective cylinder and / or depending on the peak pressure exceedance frequency (20) or intermediate pressure exceedance frequency of the respective cylinder, a cylinder-specific setpoint value for a cylinder-specific combustion position controller (30) is determined for the respective cylinder, which outputs a cylinder-specific offset value (31) as an output variable, wherein the respective cylinder-specific ignition parameter (13) is determined for each cylinder from the adapted pilot control value (22) common to all cylinders for the respective ignition parameter and the cylinder-specific offset values (31) of the cylinder-specific combustion position controller (30). [8] Method according to claim 7, characterized by that the cylinder-individual combustion position controller (30) equates cyclic fluctuations of the mean pressure or peak pressure in the cylinders, described by a variation coefficient. [9] Method according to one of claims 1 to 8, characterized by that furthermore, as a control variable for the operation of the internal combustion engine, a control value (14) for a boost pressure control element of an exhaust gas turbocharger is specified, such that depending on the knocking frequency (24) of all cylinders and / or depending on the peak pressure exceedance frequency (25) or medium pressure exceedance frequency of all cylinders, a setpoint for a nitrogen oxide controller (34) is determined, which as an output variable is a setpoint for a boost pressure regulator (38), wherein the boost pressure regulator (38) outputs the control value (14) for the boost pressure control element as an output variable. [10] Method for operating an internal combustion engine, wherein, in order to influence fuel combustion in cylinders thereof, a cylinder-specific fuel injection quantity (12) for the fuel to be burned in the respective cylinder is specified for each cylinder as a cylinder-specific control variable, such that a pilot control value (10) common to all cylinders of the internal combustion engine is specified for the fuel injection quantity, from the pilot control value (10) for the fuel injection quantity common to all cylinders, the cylinder-specific fuel injection quantity (12) is determined for each cylinder in such a way that a cylinder-specific combustion load is equal to or approximated to the fuel combustion in the cylinders of the internal combustion engine, characterized by , that furthermore, in order to influence the fuel combustion in cylinders thereof, at least one cylinder-specific ignition parameter (13) is specified for each cylinder as a cylinder-specific control variable for igniting the fuel to be burned in the respective cylinder, such that a pilot control value (11) common to all cylinders of the internal combustion engine is specified for the respective ignition parameter, from the pilot control value (11) common to all cylinders for the respective ignition parameter, an adapted pilot control value (22) common to all cylinders of the internal combustion engine for the respective ignition parameter is first determined in such a way that an average value of a combustion position of the fuel combustion in all cylinders of the internal combustion engine corresponds to a predetermined target value, from the adapted pre-control value (22) common to all cylinders for the respective ignition parameter, the respective cylinder-specific ignition parameter (13) is determined for each cylinder in such a way that a cylinder-specific combustion position in the cylinders of the internal combustion engine is equalized or approximated, Furthermore, a control value (14) for a boost pressure control element of an exhaust gas turbocharger is specified as a control variable for the operation of the internal combustion engine, such that a setpoint for a nitrogen oxide controller (34) is determined depending on the knocking frequency (24) of all cylinders and / or depending on the peak pressure exceedance frequency (25) or intermediate pressure exceedance frequency of all cylinders, which outputs a setpoint for a boost pressure controller (38) as an output variable, the boost pressure controller (38) outputting the control value (14) for the boost pressure control element as an output variable. [11] Method according to claim 10, characterized byFeatures of any one of claims 1 to 9. [12] Control unit for operating an internal combustion engine, characterized by that the same is set up to carry out the method according to one of claims 1 to 11 on the control side.

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