AT521865B1 - Method and system for simulating a number of particles emitted by an internal combustion engine - Google Patents

Abstract

The invention relates to a computer-aided method (100) for simulating a number of particles emitted by an internal combustion engine, the number of particles emitted during a combustion process in the internal combustion engine being described by means of an empirical simulation model, which has operating parameters of the internal combustion engine as input parameters and at least the number of particles as output parameters, with the empirical simulation model is based on measurements on the internal combustion engine, comprising the following work steps: determining (101a) a first operating parameter of the internal combustion engine, in particular a load gradient; - Checking (102) whether the first operating parameter lies within or outside of a predefined value range which characterizes a dynamic of the operation of the internal combustion engine; and - determining (103), if the first operating parameter lies outside the predefined value range, the number of particles by means of an empirical simulation model; or - determining (106), if the first operating parameter lies within the predefined value range, the number of particles by means of a modified simulation model which is based on the empirical simulation model; and - outputting (107) the number of particles.

Description

description

METHOD AND SYSTEM FOR SIMULATING A NUMBER OF PARTICLES EMITTED BY A COMBUSTION ENGINE

The invention relates to a computer-aided method for simulating a number of particles emitted by an internal combustion engine, the number of particles emitted during a combustion process in the internal combustion engine being described by means of an empirical simulation model which has operating parameters of the internal combustion engine as input parameters and at least the number of particles as output parameters, and the empirical simulation model is based on measurements on the internal combustion engine.

Various approaches to model-based optimization of technical facilities are known from the prior art. In particular in the area of optimization in the development or calibration of internal combustion engines, the following methods are used:

Document EP 1 150 186 A1 relates to a method for automatically optimizing an output variable of a system dependent on several input variables, for example an internal combustion engine, while observing secondary conditions, with a theoretical value for the output variable and the secondary conditions using a model function with the input variables can be determined as variables and one of the input variables is changed in successive individual steps within a variation space. Values for output variables and secondary conditions corresponding to the respective input variables are determined directly on the system and used to correct the model functions until the model functions meet the secondary conditions and achieve optimum values for the output variable.

The document WO 2013/131836 A2 relates to a method for optimizing internal combustion engines, in particular for optimizing emissions and consumption, in which at least one of the secondary influencing variables is set in this way via correction functions in their control units at each operating point given by the parameters temperature, load and speed that the emission limit values are complied with in different load speed ranges and in different temperature ranges. In a first step, a test tape for the operating points and secondary influencing variables is created using mathematical models of the control unit function and the internal combustion engine in relation to the variable to be optimized and run on the test bench; in a second step, a model for each is assigned from the data measured on the test bench Optimizing variable is created and in a third step, based on this created model, the optimal values of the secondary influencing variables are determined in compliance with the emission limit values and these values are used for the initial data entry of the correction functions by the control unit.

Document EP 1 703 110 A1 relates to a method for optimizing the calibration of internal combustion engines taking into account dynamic changes in the state of the engine and using a neural network, the calibration test starting from a start condition and defined changes in the parameters being set for calibration.

[0006] The document WO 2016/170063 A1 discloses a method and system for model-based optimization or calibration. The soot emission can be determined there using empirical models.

It is an object of the invention to improve the powertrain development process. In particular, it is an object of the invention to improve the model-based emission calibration of a drive train, in particular an internal combustion engine.

[0008] This object is achieved by a computer-aided method with a system according to the independent claims. Advantageous refinements are provided in the dependent

Claims claimed.

A first aspect of the invention relates to a computer-based method for simulating a number of particles emitted by an internal combustion engine, the number of particles emitted during a combustion process in the internal combustion engine being described by means of an empirical simulation model, which operating parameter of the internal combustion engine is the input parameter and at least the number of particles is the output parameter wherein the empirical simulation model is based on measurements on the internal combustion engine, having several or all of the following work steps:

[0010] Determination of a first operating parameter of the internal combustion engine, in particular a load gradient;

Check whether the first operating parameter lies within or outside of a predefined value range, which characterizes a dynamic of the operation of the internal combustion engine;

[0012] determining, if the first operating parameter lies outside the predefined value range, the number of particles by means of an empirical simulation model; or, if the first operating parameter lies within the predefined value range, the number of particles by means of a modified simulation model which is based on the empirical simulation model;

[0013] Output of the number of particles.

[0014] The number of particles output can preferably be used for calibration, optimization and / or control of the real or simulated internal combustion engine and / or its control. More preferably, the method can therefore have a work step of calibrating, optimizing and / or controlling the real or simulated internal combustion engine on the basis of the determined number of particles.

[0015] Output within the meaning of the invention is, in particular, provision at a data interface and / or a user interface.

Determination within the meaning of the invention is, in particular, simulation, measurement and / or reading. A determination within the meaning of the invention is, in particular, a calculation or looking up, for example in a look-up table.

A range of values in the sense of the invention is preferably defined by two threshold values or also by one threshold value and can be open to zero or infinity on one of the sides of the one threshold value. A value range can in particular also have two sub-value ranges.

The invention is based in particular on the knowledge that the particle emission can be mapped much more realistically by taking dynamic components into account for the simulation of a drive train. According to the invention, therefore, when a first operating parameter which characterizes the dynamics of the operation of the internal combustion engine, in particular the load gradient, lies in a predetermined value range, a modified simulation model based on the empirical simulation model is used.

In an advantageous embodiment of the method according to the invention, the modified simulation model is determined by modifying the empirical simulation model by means of a correction function, the correction function preferably being offset as a correction parameter, in particular as a correction factor, with the empirical simulation model.

The use of a correction function to take into account the dynamics of the engine operation enables a particularly flexible adaptation of the empirical simulation model to different dynamic situations and courses. In this way, a particularly realistic simulation result can be achieved.

In a further advantageous embodiment of the method according to the invention, the correction function is time-dependent and / or the correction parameter can have a value between 1 and

assume a predefined maximum value.

A particularly realistic simulation can also be achieved through the time dependency and a function value that is dependent on the time or another parameter.

In a further advantageous embodiment of the method according to the invention, the correction function depends on the first, in particular filtered, operating parameter, one of at least two curves and / or one of at least two maximum values for the correction function being preferably selected as a function of the first operating parameter , which each characterize a slow dynamic and a fast dynamic.

The inventor has established that it is particularly decisive for the number of particles how fast a dynamic occurs. In order to still achieve a model with a relatively low complexity and in particular to ensure its applicability in a real-time capable development environment (e.g. hardware-in-the-loop), it has proven to be particularly advantageous to distinguish between two dynamic courses.

In a further advantageous embodiment of the method according to the invention, a first profile and / or a first maximum value is selected when the first operating parameter within the predefined value range assumes a first predefined partial value range which corresponds to the slower dynamics, or where a second profile and / or a second maximum value is selected if the first operating parameter within the predefined value range assumes a second predefined partial value range which corresponds to the faster dynamics.

[0026] The first operating parameter advantageously also characterizes the speed of the dynamics. The first predefined partial value range is therefore preferably essentially lower than the second predefined partial value range and the first profile is preferably more damped than the second profile and / or the second maximum value is higher than the first maximum value. The course and the maximum value in the respective partial value range depend, however, on the underlying empirical simulation model of the respective motor, so that the specified relationships can also be reversed.

In a further advantageous embodiment of the method according to the invention, the correction function depends on a second operating parameter, in particular the coolant temperature, the method further comprising the working step:

Check whether the second operating parameter lies within a first predefined value range, which characterizes the presence of the operating temperature of the internal combustion engine;

where at least one course of the correction function is damped and / or at least one maximum

value of the correction function is reduced if the second operating parameter is within the first

th predefined range of values.

The inventor has found that taking into account a correction function for generating the modified empirical simulation model results in a particularly realistic simulation if the correction function additionally depends on a second operating parameter. The operating temperature of the internal combustion engine, which can preferably be determined via the coolant temperature, was identified as a particularly characteristic dependency of the number of particles emitted. If the internal combustion engine has reached such an operating temperature, a lower number of particles is emitted.

In a further advantageous embodiment of the method according to the invention, depending on the second operating parameter, one of at least two curves and / or one of at least two maximum values is selected for the correction function, which each characterize a cold start and a warm-up phase.

It has also proven to be particularly advantageous to choose different curves and / or maximum values for the cold start and warm-up phase. The temperature in the warm-up phase

is preferably well below the operating temperature range of the internal combustion engine.

In a further advantageous embodiment of the method according to the invention, the correction function is dependent on a second operating parameter, in particular the coolant temperature, the method further comprising the following work steps:

Check whether the second operating parameter is within a second predefined value range, which characterizes a warm-up phase of the internal combustion engine, or within a third predefined value range, which characterizes a cold start phase of the internal combustion engine; and

Selecting a third curve and / or a third maximum value when the first operating parameter assumes a first predefined partial value range within the predefined value range (“slow”), which corresponds to a slower dynamic, and the second operating parameter is within the second predefined value range (warm-up phase); or selecting a fourth curve and / or a fourth maximum value if the first operating parameter assumes a first predefined partial value range within the predefined value range (“slow”) and the second operating parameter is within the third predefined value range (cold start phase); or

Selecting a fifth curve and / or a fifth maximum value if the first operating parameter assumes a second predefined partial value range within the predefined value range (“fast”), which corresponds to the faster dynamics, and the second operating parameter is within the second predefined value range (warm-up phase); or selecting a sixth curve and / or sixth maximum value when the first operating parameter assumes a second predefined partial value range within the predefined value range (“fast”) and the second operating parameter is within the third predefined value range (cold start phase).

The inventor has found that the consideration of the similarity of the dynamics and the respective temperature during operation of the internal combustion engine are correlated, so that theoretically a correction function would have to be designed as a multi-dimensional map. In order to simplify the method, as defined above, a distinction is preferably made between only four cases of multivariate dependency.

Preferably, the first predefined partial value range of the first operating parameter is therefore essentially lower than the second predefined partial value range and wherein the second predefined value range of the second operating parameter is essentially higher than the third predefined value range; the second and the third predefined value range of the second operating parameter are preferably lower than a first predefined value range and the third profile is preferably more attenuated than the fourth profile; the fourth curve is preferably more dampened than the fifth curve, and the fifth curve is preferably more dampened than the sixth curve; the third maximum value is preferably lower than the fourth maximum value, the fourth maximum value is preferably lower than the fifth maximum value, the fifth maximum value is preferably lower than the sixth maximum value. The course and the maximum value in the respective partial value range depend, however, on the underlying empirical simulation model of the respective motor, so that the specified relationships can also be reversed.

In a further advantageous embodiment of the method according to the invention, at least one curve of the correction function is amplified and / or at least one maximum value of the correction function is increased when the first operating parameter lies within the first or second predefined partial value range.

In general, the inventor has found that a dynamic, regardless of the temperature of the operation of the internal combustion engine, results in an increased number of particles in the emission. This is hereby taken into account.

A second aspect of the invention relates to a system for simulating one of one

Internal combustion engine emitted particle number, having:

Storage means in which an empirical simulation model is stored or can be stored which describes the number of particles emitted during a combustion process in the internal combustion engine, which operating parameters of the internal combustion engine have as input parameters and at least the number of particles as output parameters and which is based on measurements on the internal combustion engine is based;

[0040] Means for determining a first operating parameter of the internal combustion engine, in particular a load gradient;

Means for checking whether the first operating parameter is within a predefined value range; and

Means for determining, if the first operating parameter is outside the predefined value range, the number of particles using the empirical simulation model or for determining, if the first operating parameter is within the predefined value range, the number of particles using a modified simulation model based on the empirical simulation model ; and

[0043] an interface for outputting the number of particles.

A means within the meaning of the present invention can be designed in terms of hardware and / or software, in particular a processing unit (CPU) and in particular a digital processing unit (CPU) and preferably connected to a memory and / or bus system / or have one or more programs or program modules. The CPU can be designed to process commands that are implemented as a program stored in a memory system, to acquire input signals from a data bus and / or to output output signals to a data bus. A storage system can have one or more, in particular different, storage media, in particular optical, magnetic, solid-state and / or other non-volatile media. The program can be designed in such a way that it embodies or is able to execute the methods described here, so that the CPU can execute the steps of such methods and thus in particular control and / or monitor a reciprocating piston engine. In particular, the means can be designed as so-called controllers.

The features and advantages described above in relation to the first aspect of the invention also apply to the second aspect of the invention and vice versa.

Further features and advantages emerge from the following description with reference to the figures. These show at least partially schematically:

[0047] FIG. 1 shows an exemplary embodiment of a method and a system for simulating a number of particles emitted by an internal combustion engine; and

Figure 2 is a diagram of a correction function for modifying an empirical simulation model.

A method for simulating a number of particles emitted by an internal combustion engine and a system 10 which is suitable for carrying out such a method 100 are explained with reference to FIG. 1.

To simulate the number of particles, an empirical simulation model is preferably set up. This is determined on the basis of a large number of stationary measurements of the internal combustion engine or on a vehicle on a test bench. For example, an engine test stand or a drive train test stand or a roller test stand can be used as the test stand.

Furthermore, on the basis of the measurement data obtained in the stationary measurements, the input parameters are defined in the empirical simulation model. These input parameters can preferably be determined by means of a sensitivity analysis. Possible parameters here are the air ratio lambda, the injection time (SOI) and

the start of burning (SOC) in question. Other or further operating parameters of an internal combustion engine can preferably also be used as input parameters. The times are preferably specified here as the distance from the upper crankshaft dead center (ignition TDC).

When generating the empirical simulation model, an assignment rule is set up between the input parameters and the number of particles as output parameters. For this purpose, approximation functions, which form the basis for the empirical simulation model, are preferably generated from the large number of measurements by means of fitting processes. These approximation functions are preferably polynomial functions and furthermore preferably cubic up to the 4th order.

In the empirical simulation model, the injection strategy is preferably also taken into account, in particular whether it is a single, double or triple injection.

In order to determine the respective value of the particle number, one or more values of a load gradient is or are preferably initially determined as the first operating parameter of the internal combustion engine, 101a. The load gradient indicates the change in the power required by the internal combustion engine and can therefore be used to characterize various emission states of the internal combustion engine. The load gradient can preferably be determined directly on the internal combustion engine. More preferably, however, this can also be determined indirectly from a further operating parameter, for example a change in the air mass flow in the internal combustion engine, in particular the air mass flow in the intake tract and / or in the exhaust system.

The determination of a respective operating parameter can preferably be done by simulating, in particular as the starting value of a simulation of an internal combustion engine, by measuring on a real internal combustion engine or simply by reading in values at a data interface. A system 10 for simulating a number of particles emitted by an internal combustion engine preferably has a simulation device, a measuring device or a data interface for reading in data 12 for this purpose.

In a further work step 102 it is checked whether the determined load gradient lies within or outside of a predefined value range.

For this purpose, the system 10 preferably has means for checking whether the first operating parameter lies within a predefined value range. The means 13 for checking is preferably a module of a computing device, in particular a logic circuit.

For this purpose, the load gradient is preferably filtered by means of an average value filter which determines the moving average value of the load gradient. The filtering ensures a more robust determination of dynamic operation of the internal combustion engine. This is particularly advantageous on virtual test benches or hardware-in-the-loop environments and / or when processing signals that may be noisy.

By using a mean value filter, individual values which have local deviations, so-called outliers, lose their importance when a dynamic operation is determined.

The filtering or smoothing of the load gradient is preferably carried out directly on the load signal or on that operating parameter of the signals from which the load gradient is derived, in particular the air mass flow or the change in the air mass flow.

Since the dynamics define a relatively large operating range of the internal combustion engine, a further distinction is preferably made in the dynamic operating range between what is known as faster dynamics and what is known as slower dynamics. These are preferably set again by two predefined partial value ranges within the predefined value range which characterizes the dynamics of the operation of the internal combustion engine.

Preferably, there are two for each of the two types of dynamics to be distinguished

various mean value filters are used. These differ in particular in the different averaging times. An averaging time of 100 ms is preferably used to calculate the moving average in the case of faster dynamics. In contrast, when calculating the moving average for slower dynamics, an averaging time of approximately 300 ms is preferably used.

The faster dynamics mainly concern operating ranges of starting, in particular also the repeat starts of the internal combustion engine in start / stop systems, and of fast accelerations, in which relatively high values of the load gradient occur. The slower dynamics, on the other hand, tend to affect operating areas that correspond to moderate acceleration processes.

If a dynamic is determined, the number of particles is preferably determined in a work step 106 by means of a modified simulation model.

Both the empirical simulation model and the modified simulation model are preferably stored in a storage means 11, which is designed in particular as a non-volatile data memory.

The modified simulation model is based on the empirical simulation model, but is offset with a correction function f. The correction function can preferably be designed as a correction parameter or a correction factor.

Preferably, as shown in FIG. 2, the correction function is time-dependent. The correction function f or its course covers a time span of a dynamic in which an increase becomes effective.

As shown in FIG. 2, the correction factor is preferably between 1 and a maximum value fmax. Both the course of the correction function f and the maximum correction factor fmax can be different for the faster dynamics and the slower dynamics. The correction function f preferably has a lower correction factor fmax and / or a flatter increase in the correction factor for the slower dynamics. The course and the maximum value for the respective dynamics, however, depend on the underlying empirical simulation model of the respective motor, so that the specified relationships can also be reversed.

If the load gradient is outside the predefined value range, i. H. If no dynamics are determined in work step 102, then in a work step 103 the number of particles is determined by means of the, in particular unchanged, empirical simulation model.

To calculate the number of particles by means of the empirical simulation model or the modified simulation model, the system preferably has means 14 for determining the number of particles. These means 14 are also preferably implemented by a module of a computing device, in particular a logic circuit.

The particle number determined for a specific operating range of the internal combustion engine is output in a work step 107. The system 10 preferably has an interface 15, in particular a user interface or a data interface, for outputting the number of particles.

Further preferably, when determining the number of particles during a dynamic of the operation of the internal combustion engine, further operating parameters, in particular the temperature of the operation of the internal combustion engine, are taken into account as a second operating parameter.

The operating temperature, which corresponds in particular to the coolant temperature of the internal combustion engine, can be taken into account in the modified simulation model, in particular in its correction function, or it can be stored as a sub-model of the modified simulation model with its own correction function.

For this purpose, the temperature of the internal combustion engine is preferably determined in a work step 101b. As in the case of the first operating parameter, in particular the load gradient,

the determination can be carried out by means of measurements, simulation or simply reading in via an interface.

This working step can also preferably be carried out by the means 12 for determining a first operating parameter.

Finally, it is also checked with regard to the temperature as a second operating parameter whether this lies within a first predefined value range which characterizes the presence of the operating temperature of the internal combustion engine. The internal combustion engine is therefore in the normal operating state in this value range. In this case, the course of the correction function is damped in a work step 105a and / or at least one maximum value fmax of the correction function is reduced if a dynamic of the operation of the internal combustion engine was determined in work step 102.

The inventor has found that the influence of the dynamics on the number of particles emitted is only less pronounced after the internal combustion engine has reached the regular operating temperature. This is taken into account by damping the course of the correction function f or reducing its maximum value fmax.

Preferably, in step 104 it can also be checked whether the temperature of the operation of the internal combustion engine, in particular the coolant temperature, lies in a second predefined value range or a third predefined value range. The second predefined value range stands for temperatures in a warming-up phase of the internal combustion engine, the third predefined value range for the coolant temperature preferably stands for a lower temperature in the cold start phase of the internal combustion engine.

On the basis of the respective value of the first operating parameter and the second operating parameter, in the present exemplary embodiment the load gradient and the coolant temperature of the internal combustion engine, different curves and / or maximum values fmax of the correction function f are then selected, 105b, 105c, 105d, 105e .

If the load gradient is in a first predefined partial value range within the predefined value range and the second operating parameter is within the second predefined value range, then in a work step 105b a third course and / or a third maximum value fmax of the correction function f is selected. This corresponds to a slower dynamic in the warm-up phase of the internal combustion engine.

If the load gradient assumes a first predefined partial value range within the predefined value range and the coolant temperature is within the third predefined value range, a fourth profile and / or a fourth maximum value fmax of the correction function f is selected in a work step 105c. This selection corresponds to a slow dynamic in a cold start phase of engine operation.

If the load gradient assumes a second predefined partial value range within the predefined value range and the coolant temperature is within the second predefined value range, a fifth profile and / or a fifth maximum value fmax of the correction function f is selected in a work step 105d. This selection corresponds to faster dynamics in the warm-up phase of the internal combustion engine.

If the load gradient assumes a second predefined partial value range within the predefined value range and the second operating parameter is within the third predefined value range, a sixth profile and / or a sixth maximum value fmax of the correction function f is selected in a work step 105e. This selection corresponds to the selection in an engine operation with faster dynamics in the cold start phase.

The first predefined partial value range is therefore preferably smaller than the second predefined partial value range of the predefined value range of the first operating parameter, in the present case the load gradient. Furthermore, the first predefined value range of the second operating parameter, in the present case the coolant temperature, is thus higher than the second predefined value range, which in turn is higher than the third predefined

Range of values is.

The empirical simulation model is changed by means of the correction function or a course of the correction function adapted to the respective operating conditions, so that the modified simulation model is produced. With the aid of this modified simulation model, the number of particles emitted at each point in time is again determined in work step 106. This number of particles is finally output in a work step 107.

It should be noted that the advantageous exemplary embodiments are merely examples that are not intended to limit the scope of protection, the application and the structure in any way. Rather, the preceding description provides the person skilled in the art with guidelines for the implementation of at least one exemplary embodiment, with various changes, in particular with regard to the function and arrangement of the described components, being able to be made without departing from the scope of protection as can be derived from the Claims and these equivalent combinations of features results.

Claims (15)

Claims 1. Computer-aided method (100) for simulating a number of particles emitted by an internal combustion engine, where the particulate matter emitted during a combustion process in the internal combustion engine number is described using an empirical simulation model, which operating parameters meter of the internal combustion engine as an input parameter and at least the number of particles as Output parameters, where the empirical simulation model is based on measurements at the combustion engine is based, having the following work steps: Determining (101a) a first operating parameter of the internal combustion engine, in particular a load gradient and / or an air mass flow gradient; - Checking (102) whether the first operating parameter lies within or outside of a predefined value range which characterizes a dynamic of the operation of the internal combustion engine; and - Determining (103), if the first operating parameter lies outside the predefined value range, the number of particles by means of the empirical simulation model; or - Determining (106), if the first operating parameter lies within the predefined value range, the number of particles by means of a modified simulation model which is based on the empirical simulation model; and - Output (107) the number of particles. 2. The method (100) according to claim 1, wherein the modified simulation model is determined by modifying the empirical simulation model by means of a correction function (f), the correction function preferably being offset as a correction parameter, in particular as a correction factor, with the empirical simulation model. 3. The method (100) according to claim 1 or 2, wherein the correction function (f) is time-dependent and / or wherein the correction parameter can assume a value between 1 and a predefined maximum value (fmax). 4. The method (100) according to claim 2 or 3, wherein the correction function (f) depends on the first, in particular filtered, operating parameter, with one of at least two courses and / or one of at least two maximum values ( fmax) is selected for the correction function, each characterizing a slower dynamic and a faster dynamic. 5. The method (100) according to claim 4, wherein a first profile and / or a first maximum value (fmnax) is selected when the first operating parameter within the predefined value range assumes a first predefined partial value range which corresponds to the slower dynamic, or a second Course and / or a second maximum value (fmax) is selected when the first operating parameter within the predefined value range assumes a second predefined partial value range which corresponds to the faster dynamics. 6. The method (100) according to claim 5, wherein the first predefined partial value range is essentially lower than the second predefined partial value range and wherein the first curve is preferably essentially more attenuated than the second curve and / or the second maximum value (fmax) is preferably essentially higher than the first maximum value (fmax) is. 7. The method (100) according to any one of claims 2 to 6, wherein the correction function depends on a second operating parameter, in particular the coolant temperature, the method further comprising the step: Determining (101b) a second operating parameter of the internal combustion engine, in particular a temperature of the operation of the internal combustion engine, preferably the coolant temperature; Check (104) whether the second operating parameter is within a first predefined 10. 11. 12. Austrian AT 521 865 B1 2020-10-15 Range of values, which characterizes the presence of the operating temperature of the internal combustion engine; wherein at least one curve of the correction function is damped and / or at least one maximum value (fmax) of the correction function is reduced (105a) if the second operating parameter lies within the first predefined value range. Method according to one of Claims 2 to 7, in which, depending on the second operating parameter, one of at least two courses and / or one of at least two maximum values (fmax) is selected for the correction function, each characterizing a cold start and a warm-up phase. Method (100) according to one of claims 5 to 8, wherein the correction function depends on a second operating parameter, in particular a temperature of the operation of the internal combustion engine, preferably the coolant temperature, the method further comprising the following work steps: Checking (104) whether the second operating parameter is within a second predefined value range, which characterizes a warm-up phase of the internal combustion engine, or within a third predefined value range, which characterizes a cold start phase of the internal combustion engine; and Selecting (105b) a third curve and / or a third maximum value (fmax) if the first operating parameter assumes a first predefined partial value range within the predefined value range, which corresponds to a slower dynamic, and the second operating parameter lies within the second predefined value range; or selecting (105c) a fourth profile and / or a fourth maximum value (fmax) if the first operating parameter assumes a first predefined partial value range within the predefined value range and the second operating parameter is within the third predefined value range; or Selecting (105d) a fifth curve and / or a fifth maximum value (fmax) when the first operating parameter assumes a second predefined partial value range within the predefined value range which corresponds to the faster dynamics and the second operating parameter is within the second predefined value range; or selecting (105e) a sixth curve and / or sixth maximum value (fmax) if the first operating parameter assumes a second predefined partial value range within the predefined value range and the second operating parameter is within the third predefined value range. The method (100) according to claim 9, wherein the first predefined partial value range of the first operating parameter is essentially lower than the second predefined partial value range and wherein the second predefined value range of the second operating parameter is essentially higher than the third predefined value range, the second and the third predefined value range of the second operating parameter are preferably substantially lower than a first predefined value range and wherein the third course is preferably substantially more damped than the fourth course, the fourth course is preferably substantially more damped than the fifth course, and the fifth course is preferably substantially more damped than the sixth curve is, the third maximum value (fmax) preferably substantially lower than the fourth maximum value (fmax), the fourth maximum value (fmax) preferably substantially lower than the fifth maximum value (fmax), the five fte maximum value (fmax) is preferably substantially lower than the sixth maximum value (fmax). Method (100) according to one of claims 4 to 10, wherein at least one curve of the correction function is amplified and / or at least one maximum value (fmax) of the correction function is increased if the first operating parameter is within the first or second predefined partial value range of the predefined value range. Computer-aided method for calibrating an internal combustion engine, with an emitted number of particles continuously during operation of the internal combustion engine by means of a method is determined according to one of claims 1 to 11 and wherein an electronic control unit of the internal combustion engine is calibrated on the basis of the determined number of particles, in particular an accumulated number of particles. 13. Computer program comprising instructions which, when executed by a computer, cause the computer to carry out the steps of a method according to any one of claims 1 to 12. 14. Computer-readable medium on which a computer program according to claim 13 is stored or which comprises instructions which, when executed by a computer, cause the computer to carry out the steps of a method according to one of claims 1 to 12. 15. System (10) for simulating a number of particles emitted by an internal combustion engine, comprising: storage means (11) in which an empirical simulation model is or can be stored which describes the number of particles emitted during a combustion process in the internal combustion engine, which operating parameter of the internal combustion engine is the input parameter and at least the particle number as output parameter, and which is based on measurements on the internal combustion engine; Means (12) for determining a first operating parameter of the internal combustion engine, in particular a load gradient; Means (13) for checking whether the first operating parameter lies within a predefined value range, which characterizes a dynamic of the operation of the internal combustion engine; and means (14) for determining, if the first operating parameter is outside the predefined value range, the number of particles using the empirical simulation model or for determining, if the first operating parameter is within the predefined value range, the number of particles using a modified simulation model based on the empirical simulation model is based; and an interface (15) for outputting the number of particles. For this purpose 2 sheets of drawings