DE102018207467A1 - Method for calculating a fresh air mass in a cylinder and control - Google Patents

Abstract

The invention relates to a method for calculating a fresh air mass in a cylinder (2) of an internal combustion engine (1), comprising: determining (36) heating of the fresh air (7) on a wall (2a) of the cylinder (2), wherein the temperature the wall (2a) of the cylinder changes dynamically; andcalculating (41) the fresh air mass of the fresh air (7) in the cylinder (2) based on the determined heating of the fresh air mass.

Description

The invention relates to a method for calculating a fresh air mass in a cylinder of an internal combustion engine and to a controller that is configured to carry out such a method.

When gasoline engine, it is well known to determine the amount of air in the combustion chamber of a cylinder as accurately as possible, so that the correct amount of fuel for the injection can be calculated. The amount of air remaining in the combustion chamber is dependent on many thermodynamic parameters and it is known that filling errors in the calculated amount of air can occur under other ambient temperatures.

From the German patent application DE 101 58 261 A1 An engine management system is known in which a physically based model is used to determine various state variables. The state quantities are related to a connection portion interposed between a mixing point where recirculated exhaust gas is mixed with intake fresh air and intake valves of an internal combustion engine. The physical model simulates the behavior of this connection section so that various operating parameters of the internal combustion engine can be controlled using this model, such as the fresh air mass in the connection section and the gas temperature. The disadvantage of this is that only the influence of the connecting portion is taken into account on the fresh air mass, but ignore other influences on the fresh air mass.

Object of the present invention is to provide a method for calculating a fresh air mass in a cylinder of an internal combustion engine and a corresponding control for an internal combustion engine, which at least partially overcome the above-mentioned disadvantages.

This object is achieved by the method according to claim 1 and the control according to claim 15.

According to a first aspect, the present invention provides a method for calculating a fresh air mass in a cylinder of an internal combustion engine, the method comprising: determining a heating of the fresh air at a wall of the cylinder, wherein the temperature of the wall ( 2a ) of the cylinder changed dynamically; and calculating the fresh air mass of the fresh air in the cylinder based on the determined heating of the fresh air mass.

In a second aspect, the present invention provides a controller for an internal combustion engine having at least one cylinder, a draft tube, a port temperature sensor, an intake valve on the cylinder, and an intake port in front of the intake valve, the controller configured to follow the method of the first embodiment To perform aspect.

Further advantageous embodiments of the invention will become apparent from the subclaims and the following description of preferred embodiments of the present invention.

In some embodiments, an increase in the fresh air temperature is calculated from a temperature sensor in the intake manifold to the intake valve, wherein the heat exchange over the temperature difference between the component and fresh air is calculated. In addition, in some embodiments, the internal combustion engine has a controlled cooling water mass flow (KFKM) and thus an additional degree of freedom and it has been recognized that this degree of freedom has not been sufficiently considered in known in the art solutions or Füllungserfassungsmodellen. In addition, it has been recognized that in dynamic changes or processes, deviations in the calculated fresh air charge can occur, which deviations can always be significant if it has previously given a longer phase in the unfired engine operation (fuel injection off).

It has also been recognized that known corrections can not account for heat transients with the cylinder wall, so that at very hot or very cold intake temperatures, changes in the density of the fresh air in the combustion chamber will be overcorrected due to the unaddressed effect. This can lead to larger errors in the fresh air calculation. In addition, it was recognized that in engines with map-controlled cooling water flows, the pure cooling water temperature is not always fully meaningful, since the heat transfer to the cylinder wall can not be taken into account by heat convection depending on the water mass flow. Furthermore, it was recognized that known corrections of the injection quantity can not map the time course of the necessary mixture correction neither qualitatively nor quantitatively and it can not be distinguished whether the dynamic load change from the fired or unfired engine operating point. Due to stricter emission limits of new exhaust gas test cycles and the increased requirements under all environmental conditions to achieve lowest emissions, in some embodiments, the heating of the fresh air through the cylinder wall is taken into account.

Accordingly, some embodiments relate to a method for calculating a fresh air mass in a cylinder of an internal combustion engine, the method comprising determining a heating of the fresh air at a wall of the cylinder, wherein the temperature of the wall of the cylinder changes dynamically, and calculating the fresh air mass of the fresh air in the cylinder based on the determined heating of the fresh air mass.

The internal combustion engine may be a gasoline engine or diesel engine or the like and, for example, be provided for a motor vehicle (such as a car, motorcycle, but in principle also other land, water and / or aircraft). The number of cylinders is arbitrary and may vary depending on the embodiments 1 . 2 . 3 . 4 . 5 . 6 , etc.

The fresh air mass is in some embodiments directly the mass of fresh air in the cylinder, for example, directly after a suction without the invention should be limited in this regard, whereas in other embodiments, the fresh air mass is represented by one or more sizes, such as. Density, temperature, volume, etc.

The method now determines the heating of the fresh air in the cylinder on a wall of the cylinder even at a dynamically changing temperature of the wall of the cylinder. In this case, the portion of the cylinder wall which has contact with the fresh air, which, for example, enters the cylinder for subsequent combustion by an intake process, is considered, since the aim in some embodiments is to determine the correct amount of fuel to be injected based on the fresh air mass present in the cylinder to determine. This section can be, for example, the section of the cylinder wall in the combustion chamber of the cylinder, the cylinder bottom (or piston surface), etc.

The method then calculates the fresh air mass of the fresh air in the cylinder based on the determined heating of the fresh air mass.

Thus, embodiments of the invention make it possible to take into account the heating of the fresh air on the cylinder wall even with dynamic changes in the temperature of the cylinder wall during the intake phase and thus increase the accuracy of the calculated fresh air mass. Thereby, in some embodiments, a higher mixture accuracy between air and fuel can be achieved at deviating from the standard state intake temperatures, coolant temperatures and coolant mass flows through the cylinder crankcase or through the cylinder head. This temperature correction goes beyond temperature corrections, in which only the heating up to the inlet valve is modeled. The additional integration of the cylinder wall temperature as a heat contact surface has the advantage that in particular the filling errors are reduced under other ambient temperatures. In some embodiments, a coolant mass flow can also be integrated in the heat transfer by means of heat convection. The aim of the method is therefore, in some embodiments, to consider the heating of the fresh air to the cylinder wall during the intake phase. For this purpose, as mentioned, the current high-dynamic cylinder wall temperature is determined because z. B. just after cooling phases in the unfired thrust or in a Niedrigst load range, the temperature of the cylinder wall drops sharply. In a dynamic change of the engine operating point or the operating point of the internal combustion engine in a higher load range, the cylinder wall heats up delayed to a stationary state. In some embodiments, these warm-up and cooling processes are modeled as accurately as possible and taken into account their influence on the fresh air filling. Thus, some embodiments provide higher vehicle dynamics and lower load changes and lower exhaust emissions during load changes, especially from overrun phases and FMA concepts ("freewheel engine off"). In addition, some embodiments have the advantage that the dynamic correction of the fresh air temperature based on the warm-up and cool-down operations of the cylinder wall improves the mixture accuracy in dynamics. The exhaust emissions can occur more intensely in the dynamics to which control systems such as the lambda control and the mixture adaptation partially react only delayed to compensate for the filling errors, so that some embodiments can reduce filling errors by dynamically correcting the fresh air temperature.

In some embodiments, determining the heating of the fresh air includes determining the heating of the fresh air, assuming a constant temperature of the wall of the cylinder. A Constant temperature of the cylinder wall corresponds in some embodiments, a stationary operating condition of the internal combustion engine. The determination of the heating at an assumed constant temperature of the cylinder wall is simpler and can be used as a starting point for the calculation of the heating of the fresh air at a dynamic temperature change of the cylinder wall.

In some embodiments, the stationary cylinder wall temperature can vary greatly at a change in operating point of the internal combustion engine, z. B. 180 K, without the present invention should be limited in this regard. Since the stationary state typically sets only after a few seconds, the not yet steady cylinder wall temperature affects the intake fresh air mass. During load changes from a "cold" to a "warm" operating point of the internal combustion engine, a density advantage is established and with reverse load changes, a density disadvantage arises, which can have an effect until the stationary cylinder wall temperature is reached. This can lead to fill errors if the effect is not taken into account.

In some embodiments, the determined heating of the fresh air is filtered by assuming a constant temperature of the wall of the cylinder through a filter to determine a dynamic correction of the heating of the fresh air to the wall of the cylinder. If the heating of the fresh air is determined on the assumption of a constant temperature of the cylinder wall, ie at a stationary operating point of the internal combustion engine, this leads to a profile of the temperature of the fresh air, which is closer to a real course, as well 1 illustrated.

In 1 is the cylinder wall temperature "T _Zyl-w " in Kelvin on the ordinate and the time "t" on the abscissa in seconds. 1 shows a course 100 a temperature of the fresh air as a function of the cylinder wall temperature and the time, as it results when a constant temperature of the cylinder wall for the calculation of the heating of the fresh air is assumed at the cylinder wall. The history 100 is characterized by an instantaneous steep or vertical temperature jump from 320 K to 500 K, ie by a difference of 180 K (ie 180 ° C). This is due to the fact that assuming a constant temperature of the cylinder wall for the calculation of the temperature increase of the fresh air, no continuous temperature increase is possible, leading to this artificial jump in the course 100 leads. In contrast, a course shows 101 a simulation, as theoretically a natural course of the cylinder wall temperature could look like, whereby the course 101 based on a simulation of a dynamic change in the cylinder wall temperature. A course 102 now illustrates the heating of the fresh air at the cylinder wall, when it is filtered by a filter corresponding to the jump in the course 100 changed so that the warming of the fresh air is not sudden, but continuously and approaches a natural history.

By providing such a filter, a simple and cost-effective correction of the dynamic heating of the fresh air at the dynamically changing temperature of the cylinder wall is possible.

In some embodiments, the filter has at least one PT1 filter. PT1 filters are basically known and are simple and inexpensive to provide. In some embodiments, the filter has two series-connected PT1 filters, which produce a particularly good temperature profile of the fresh air at a dynamic cylinder wall temperature.

In some exemplary embodiments, the filter is determined empirically, for example on a test bench, so that it can be adapted to a specific internal combustion engine or a concrete model of an internal combustion engine.

In some embodiments, the filter depends on at least one parameter that is characteristic of the temperature of the wall of the cylinder, so that a well adapted dynamic heating of the fresh air can be achieved in this way for different temperatures and temperature profiles of the cylinder wall temperature.

In some embodiments, the parameter represents an amount of heat introduced during combustion, a speed of the internal combustion engine, and / or a heat transfer of cooling water to the wall of the cylinder. On the basis of these parameters, the temperature change of the cylinder wall and thus the change in temperature of the fresh air can be well determined.

In some embodiments, as will be explained below, the filtered heating is multiplied by an effective and dynamic heat transfer coefficient. As a result, a correction temperature can be obtained, which is a dynamic temperature change of the cylinder wall considered. In addition, the dynamic heat transfer coefficient takes into account the heat transfer from the cylinder wall to the fresh air with dynamic temperature change.

In some embodiments, the effective and dynamic heat transfer coefficient is determined empirically, so that it does not have to be complicated in a controller, but, for example, is present as a map. The effective and dynamic heat transfer coefficient can be determined, for example, on a test bench for a specific type of internal combustion engine.

In some embodiments, determining the heating of the fresh air at the wall of the cylinder, wherein the temperature of the wall of the cylinder changes dynamically, the addition of the determined heating of the fresh air, assuming a constant temperature of the wall of the cylinder and the dynamic correction of the heating the fresh air on the wall of the cylinder. For a very simple consideration of the dynamic heating of the cylinder wall and thus the fresh air is possible.

In some embodiments, the method further includes determining a reference heating of the fresh air of the wall of the cylinder based on at least one reference parameter, as further discussed below. The reference heating can be easily determined empirically on a test bench and thus simplifies the overall determination of the heating of the fresh air.

In some embodiments, the fresh air mass of the fresh air in the cylinder is calculated based on the determined heating of the fresh air mass and the determined reference heating, as also shown in more detail below.

In some embodiments, therefore, the existing temperature correction of the fresh air (mass) is extended in the intake to behind the inlet valve to the wall heat exchange between the cylinder wall and the fresh air and corrected in particular by the dynamic change in temperature by the dynamic change in temperature of the cylinder wall.

Generally, in some embodiments, the temperature increase of the fresh air on the way into the cylinder may be determined based on the following equation: $${\text{T}}_{\text{Luft\_kor}\text{i}}={\mathrm{\alpha }}_{\text{w}\text{i}}\cdot \left({\text{T}}_{\text{w}\text{, l}}-{\text{T}}_{\text{air}\text{i}-1}\right)+{\text{T}}_{\text{air}\text{i}-1}$$

The parameter "i" represents a component that releases heat to the fresh air on its way into the cylinder, so that "i-1" marks the next, upstream component from which the fresh air comes.

The parameter "T _{w, i} " represents the temperature of the wall surface "w" of the component "i" for which the heat given off to the fresh air is to be determined.

The parameter "T _{air, i-1} " represents the temperature (or temperature sense) of the fresh air at the next upstream component "i-1".

wobei „Q_w“ die abgegebene Wärme an der Wand „w“ darstellt, „α_i“ den Wärmeübertragungskoeffizienten des Bauteils „i“ und „A_i“ die Kontaktfläche des Bauteils „i“:The parameter "α _{w, i} " represents an effective heat transfer coefficient for a wall section or a contact surface A _{i of} the component i, which comes into contact with the fresh air: $${\mathrm{\alpha }}_{\text{w}\text{, l}}=\left({\text{Q}}_{\text{w}}\cdot {\mathrm{\alpha }}_{\text{i}}\cdot {\text{A}}_{\text{i}}\right).$$

where "Q _w " represents the heat released on the wall "w", "α _i " the heat transfer coefficient of the component "i" and "A _i " the contact surface of the component "i":

In some embodiments, the effective heat transfer coefficient is determined empirically, for example on a test bench, and / or model-based.

In some embodiments, determining the heating of the fresh air includes determining a heating of the fresh air at an intake passage to the cylinder in front of an intake valve of the cylinder (assuming a steady-state operating condition). In some embodiments, there is, for example, a temperature sensor in a suction tube, which is located in front of the cylinder and through which Fresh air is sucked in, so that the temperature of the fresh air in the intake manifold at the location of the temperature sensor using this temperature sensor can be determined. In some embodiments, no further temperature sensor is provided after this temperature sensor, so that the inclusion of the heating of the fresh air at the inlet channel to the cylinder, the heating of the fresh air on the way from the suction pipe at the location of the temperature sensor can be calculated to the cylinder in more detail.

wobei T_{Luft_v_EV} die Temperaturerhöhung der Frischluft am Einlasskanal vorm Einlassventil des Zylinders repräsentiert, T_EK die Temperatur des Einlasskanals repräsentiert, T_{Luft_Sgr} die Temperatur der Frischluft in einem Saugrohr zum Einlasskanal des Zylinders repräsentiert und α_w1 einen effektiven Wärmeübertragungskoeffizienten des Einlasskanals repräsentiert.Determining the heating of the fresh air at the intake passage may be based on the following relationship: $${\text{T}}_{\text{Luft\_v\_EV}}=\left({\text{T}}_{\text{EV}}-{\text{T}}_{\text{Luft\_Sgr}}\right)\cdot {\mathrm{<figure-callout\; id="1"\; label="\alpha \; w"\; filenames="DE102018207467A1\_0015.png,DE102018207467A1\_0016.png"\; state="\{\{state\}\}">\alpha \; </figure-callout>}}_{\text{w}}+{\text{T}}_{\text{Luft\_Sgr}}.$$

wherein T _{Luft_v_EV represents} the temperature increase of the fresh air at the inlet _{port upstream of} the intake valve of the cylinder, T _{EK represents} the temperature of the intake _port , T _{Luft_Sgr represents} the temperature of the fresh air in a suction pipe to the intake _{port of} the cylinder and α _{w1 represents} an effective heat transfer coefficient of the intake _port .

Thus, equation (3) allows the determination of the temperature increase of the fresh air at the intake passage in front of the intake valve of the cylinder, wherein the temperature T _{Luft_Sgr of} the fresh air in a suction pipe to the intake _port of the cylinder is determined by a temperature sensor in the intake manifold, so that this temperature as a measured value is present. The temperature T _{EK of} the intake duct can be determined, for example, model-based and / or determined on the basis of a cooling water temperature.

In some embodiments, the effective heat transfer coefficient _{αw1 includes} a map representing the heat transfer of the intake _passage in response to a speed and / or an intake manifold pressure. As a result, an accurate determination of the heating of the fresh air or the heat transfer of the inlet channel to the fresh air is possible.

The effective heat transfer coefficient α _w1 can be determined by measurement on a test bench, so that the heat transfer for the internal combustion engine can be determined particularly accurately.

In some embodiments, the temperature of the fresh air is determined in the intake manifold by means of a temperature sensor in the intake manifold, so that as a starting point of the calculations for the heating of the fresh air in the intake a measured value and, for example, no model-based value for the fresh air temperature is present, whereby the accuracy improves can be.

In some embodiments, determining the heating of the fresh air includes determining a heating of the fresh air at an intake valve of the cylinder. In some embodiments, the intake valve is the next component in the intake line which is significantly involved in the heating of the intake fresh air on the way into the cylinder after the above-mentioned intake passage, so that the accuracy of the determination of the heating can be further increased.

wobei T_{Luft_h_EV} die Temperaturerhöhung der Frischluft am Einlassventil des Zylinders repräsentiert, T_EV die Temperatur des Einlassventils repräsentiert, T_{Luft_v_EV} die Temperatur der Frischluft im Einlasskanal vorm Einlassventil des Zylinders repräsentiert und α_w2 einen effektiven Wärmeübertragungskoeffizienten des Einlassventils repräsentiert.Determining the heating of the fresh air at the intake valve of the cylinder may be based on the context: $${\text{T}}_{\text{Luft\_h\_EV}}=\left({\text{T}}_{\text{EV}}-{\text{T}}_{\text{Luft\_v\_EV}}\right)\cdot {\mathrm{<figure-callout\; id="2"\; label="\alpha \; w"\; filenames="DE102018207467A1\_0015.png"\; state="\{\{state\}\}">\alpha \; </figure-callout>}}_{\text{w}}+{\text{T}}_{\text{Luft\_v\_EV}}.$$

wherein T _{Luft_h_EV represents} the temperature increase of the fresh air at the intake valve of the cylinder, T _{EV represents} the temperature of the intake valve, T _{Luft_v_EV represents} the temperature of the fresh air in the intake _passage in front of the intake valve of the cylinder and α _{w2 represents} an effective heat transfer coefficient of the intake valve.

Equation (4) thus allows the determination of the temperature increase T _{Luft_h_EV of} the fresh air at the intake valve of the cylinder, the temperature T _{Luft_v_EV} can be determined based on the equation (3) above, so that they can be particularly accurate in some embodiments. The temperature T _{EV of} the intake valve can be determined, for example, model-based and / or determined on the basis of a cooling water temperature or oil temperature of the internal combustion engine.

In some embodiments, the effective heat transfer coefficient _{αw2 includes} a map representing the heat transfer of the intake valve in response to a speed and / or an intake manifold pressure. As a result, an accurate determination of the heating of the fresh air or the heat transfer of the intake valve to the fresh air is possible.

The effective heat transfer coefficient α _w2 can be determined by measurement on a test bench, so that the heat transfer for the internal combustion engine can be determined particularly accurately or it can also be determined model-based and stored accordingly as a map.

wobei T_{Luft_Zyl_stationär} die Temperaturhöhung der Frischluft an der Wand des Zylinders repräsentiert, T_{Zyl_Wand} die Temperatur der Wand des Zylinders ist, T_{Luft_h_EV} die Temperatur der Frischluft nach dem Einlassventil des Zylinders ist und α_w3 einen effektiven Wärmeübertragungskoeffizienten der Wand des Zylinders repräsentiert (der empirisch auf dem Prüfstand und/oder modellbasiert ermittelt wird und bspw. als Kennfeld abgelegt ist).In some embodiments, determining the heating of the fresh air at the wall of the cylinder for steady state operation is based on the context: $${\text{T}}_{\text{Luft\_Zyl\_stationär}}=\left({\text{T}}_{\text{Zyl\_Wand}}-{\text{T}}_{\text{Luft\_h\_EV}}\right)\cdot {\mathrm{<figure-callout\; id="3"\; label="\alpha \; w"\; filenames="DE102018207467A1\_0015.png"\; state="\{\{state\}\}">\alpha \; </figure-callout>}}_{\text{w}}+{\text{T}}_{\text{Luft\_h\_EV}}.$$

T _{Luft_Zyl_stationär represents} the increase in temperature of the fresh air on the wall of the cylinder, T _{Zyl_Wand is} the temperature of the wall of the cylinder, T _{Luft_h_EV is} the temperature of the fresh air to the inlet valve of the cylinder and α _{w3 represents} an effective heat transfer coefficient of the wall of the cylinder (empirically is determined on the test bench and / or model-based and, for example, is stored as a map).

Equation (5) thus permits the determination of the temperature increase T _{air_zyl_stationary of} the fresh air at the wall of the cylinder in steady state operation, the temperature T _{Luft_h_EV} can be determined based on the equation (4) above, so that they are particularly accurate in some embodiments can. The temperature T _{Zyl_Wand of} the wall of the cylinder can be determined, for example, model-based. In some embodiments, the determination of the temperature T _{Zyl_Wand} the wall of the cylinder based on a simulation calculation, a thermodynamic model of the internal combustion engine is used, so that the temperature depending on, for example, a fresh air filling and a speed of the internal combustion engine can be specified and, for example, filed as a map can be. Accordingly, in some embodiments, the temperature T _{Zyl_Wand} the wall of the cylinder as a map that indicates this temperature, for example. Depending on the fresh air filling and / or the speed of the internal combustion engine. For a very accurate determination of the temperature of the wall of the cylinder and thus the heating of the fresh air is possible.

In order to take into account also the dynamic temperature change of the fresh air at the cylinder wall, at which the temperature changes dynamically, a correction factor T _{Luft_Zyl_kor_dyn is} determined. For this purpose, first of all the temperature increase T _{Luft_Zyl_stationär of} the fresh air at the cylinder wall originating from equation (5) is filtered by a filter, for example two PT1 filters connected in series, so that a filtered temperature increase T _{Luft_Zyl_PT1 of} the fresh air is obtained. This filtered temperature increase T _{Luft_Zyl_PT1} is now multiplied by the effective and dynamic heat transfer coefficient adyn, which represents the dynamic heat transfer to the fresh air from the cylinder wall and can be represented, for example, as a map and depends on at least one of the parameters: amount of incoming fresh air and speed the internal combustion engine.

Thus, the correction factor T _{Luft_Zyl_kor_dyn} can be determined as follows: $${\text{T}}_{\text{Luft\_Zyl\_kor\_dyn}}={\text{<figure-callout id="1" label="T Luft\_Zyl\_PT" filenames="DE102018207467A1\_0015.png,DE102018207467A1\_0016.png" state="{{state}}">T </figure-callout>}}_{\text{Luft\_Zyl\_PT}}\cdot {\mathrm{\alpha }}_{\text{dyn}}$$

By multiplying the temperature difference of the cylinder wall with the effective dynamic wall heat transfer coefficient results in a temperature difference for the fresh air in dynamic operating conditions, which is taken into account in the calculation of the current fresh air temperature after intake valve includes in some embodiments.

oder ausgeschrieben, das heißt T_{Luft_Zyl_stationär} ersetzt durch die Gleichung (5) oben: $${\text{T}}_{\text{Luft\_Zyl}}=\left({\text{T}}_{\text{Zyl\_Wand}}-{\text{T}}_{\text{Luft\_h\_EV}}\right)\cdot {\mathrm{\alpha }}_{\text{w}3}+{\text{T}}_{\text{Luft\_h\_EV}}+{\text{T}}_{\text{Luft\_Zyl\_kor\_dyn}}$$

The total heating T _{Luft_Zyl of} the fresh air at the cylinder wall, wherein the dynamic change of the temperature of the cylinder wall is taken into account, results from the addition of the determined heating T _{Luft_Zyl_stationär} the fresh air, assuming a constant temperature of the wall of the cylinder according to equation (5) and the dynamic correction of the heating T _{Luft_Zyl_kor_dyn of} the fresh air at the wall of the cylinder according to equation (6): $${\text{T}}_{\text{air}}={\text{T}}_{\text{Luft\_Zyl\_stationär}}+{\text{T}}_{\text{Luft\_Zyl\_kor\_dyn}}$$

or _spelled out, that is, T _{air_Zyl_stationary} replaced by the equation (5) above: $${\text{T}}_{\text{Luft\_Zyl}}=\left({\text{T}}_{\text{Zyl\_Wand}}-{\text{T}}_{\text{Luft\_h\_EV}}\right)\cdot {\mathrm{<figure-callout\; id="3"\; label="\alpha \; w"\; filenames="DE102018207467A1\_0015.png"\; state="\{\{state\}\}">\alpha \; </figure-callout>}}_{\text{w}}+{\text{T}}_{\text{Luft\_h\_EV}}+{\text{T}}_{\text{Luft\_Zyl\_kor\_dyn}}$$

In some embodiments, the method includes determining a reference heating of the fresh air to a wall of the cylinder based on at least one reference parameter, wherein the reference parameter may include, for example, reference temperatures of intake, intake port, intake valve and / or cylinder wall temperature. The reference temperatures can be chosen arbitrarily and the expert will appreciate that he can choose the temperatures according to the embodiment accordingly.

The reference heating of the fresh air on the wall of the cylinder takes place in some embodiments basically based on the same calculation rules as for the above discussed heating of the fresh air on the wall of the cylinder, in particular the equations (1) to (5), only with the difference in that said reference temperature (s) is (are) used.

Accordingly, in some embodiments, the following relationships are used to calculate the reference heating of the fresh air to the wall of the cylinder:

wobei T_{Luft_v_EV_ref} die Referenz-Temperaturerhöhung der Frischluft am Einlasskanal vor dem Einlassventil des Zylinders repräsentiert, T_{EK_ref} die Referenz-Temperatur des Einlasskanals repräsentiert (und bspw. der Referenz-Kühlwassertemperatur entspricht), T_{Luft_Sgr_ref} die Referenz-Temperatur der Frischluft in einem Saugrohr zum Einlasskanal des Zylinders repräsentiert und α_w1 einen effektiven Wärmeübertragungskoeffizienten des Einlasskanals repräsentiert, wie auch schon oben diskutiert (Gleichung (3)).Determining the reference heating of the fresh air at the intake passage may be based on the following relationship: $${\text{T}}_{\text{Luft\_v\_EV\_ref}}=\left({\text{T}}_{\text{EK\_ref}}-{\text{T}}_{\text{Luft\_Sgr\_ref}}\right)\cdot {\mathrm{<figure-callout\; id="1"\; label="\alpha \; w"\; filenames="DE102018207467A1\_0015.png,DE102018207467A1\_0016.png"\; state="\{\{state\}\}">\alpha \; </figure-callout>}}_{\text{w}}+{\text{T}}_{\text{Luft\_sgr\_ref}}.$$

wherein T _{Luft_v_EV_ref represents} the reference temperature increase of the fresh air at the intake _{passage in} front of the intake valve of the cylinder, T _{EK_ref represents} the reference temperature of the intake _passage (and corresponds, for example, the reference cooling water temperature), T _{Luft_Sgr_ref is} the reference temperature of the fresh air in a suction pipe for _{Inlet port of} the cylinder and α _{w1 represents} an effective heat transfer coefficient of the intake _passage , as discussed above (equation (3)).

wobei T_{Luft_h_EV_ref} die Referenz-Temperaturerhöhung der Frischluft am Einlassventil des Zylinders repräsentiert, T_{EV_ref} die Referenz-Temperatur des Einlassventils repräsentiert (und z. B. der Referenz-Kühlwassertemperatur entspricht), T_{Luft_v_EV_ref} die Referenz-Temperatur der Frischluft im Einlasskanal vor dem Einlassventil des Zylinders repräsentiert (und z. B. nach Gleichung (9) berechnet) und α_w2 einen effektiven Wärmeübertragungskoeffizienten des Einlassventils repräsentiert, wie auch schon oben diskutiert (Gleichung (4)).Determining the reference heating of the fresh air at the intake valve of the cylinder may be based on the relationship: $${\text{T}}_{\text{Luft\_h\_EV\_ref}}=\left({\text{T}}_{\text{EV\_ref}}-{\text{T}}_{\text{Luft\_v\_EV\_ref}}\right)\cdot {\mathrm{<figure-callout\; id="2"\; label="\alpha \; w"\; filenames="DE102018207467A1\_0015.png"\; state="\{\{state\}\}">\alpha \; </figure-callout>}}_{\text{w}}+{\text{T}}_{\text{Luft\_v\_EV\_ref}}$$

where T _{Luft_h_EV_ref represents} the reference temperature increase of the fresh air at the intake valve of the cylinder, T _{EV_ref represents} the reference temperature of the intake valve (and corresponds, for example, to the reference cooling water temperature), T _{Luft_v_EV_ref is} the reference temperature of the fresh air in the intake _passage in front of the intake valve of the cylinder (and calculates, for example, according to equation (9)) and α _{w2 represents} an effective heat transfer coefficient of the intake valve, as discussed above (equation (4)).

wobei T_{Luft_Zyl_ref} die Referenz-Temperaturhöhung der Frischluft an der Wand des Zylinders repräsentiert, T_{Zyl_Wand_ref} die Referenz-Temperatur der Wand des Zylinders ist, T_{Luft_h_EV_ref} die - Referenz-Temperatur der Frischluft nach dem Einlassventil des Zylinders ist (bspw. nach Gleichung (10) berechnet) und α_w3 einen effektiven Wärmeübertragungskoeffizienten der Wand des Zylinders repräsentiert, wie auch schon oben diskutiert (Gleichung (5)).In some embodiments, determining the reference heating of the fresh air at the wall of the cylinder is based on the relationship: $${\text{T}}_{\text{Luft\_Zyl\_ref}}=\left({\text{T}}_{\text{Zyl\_Wand\_ref}}-{\text{T}}_{\text{Luft\_h\_EV\_ref}}\right)\cdot {\mathrm{<figure-callout\; id="3"\; label="\alpha \; w"\; filenames="DE102018207467A1\_0015.png"\; state="\{\{state\}\}">\alpha \; </figure-callout>}}_{\text{w}}+{\text{T}}_{\text{Luft\_h\_EV\_ref}}$$

where T _{Luft_Zyl_ref represents} the reference temperature increase of the fresh air at the wall of the cylinder, T _{Zyl_Wand_ref is} the reference temperature of the wall of the cylinder, T _{Luft_h_EV_ref is} the reference temperature of the fresh air after the inlet valve of the cylinder (eg according to equation (10 ) and α _{w3 represents} an effective heat transfer coefficient of the wall of the cylinder, as discussed above (Equation (5)).

As mentioned, in some embodiments, the fresh air mass of the fresh air in the cylinder is calculated based on the determined heating of the fresh air mass and the determined reference heating, whereby the fresh air mass can be calculated very precisely.

The above calculations, in some embodiments, are based on the assumption that the internal combustion engine is in a steady state and, accordingly, stable temperature conditions prevail (ie, that the internal combustion engine is stable at an operating point), and then as stated above , the heating of the fresh air is corrected accordingly to the dynamic heating (see also equations (6) to (8) above).

In some embodiments, the fresh air quantity or fresh air mass in the cylinder is determined on a test bench and stored as a map, for example. The map is multi-dimensional and depends on one or more of the following parameters: speed, intake manifold pressure, camshaft position at the inlet and outlet, etc.

This fresh air quantity or fresh air mass determined on the test stand is then determined on the basis of the determined temperature (heating) of the fresh air on the cylinder wall (according to equation (7) or (8)) and the reference temperature (warming) of the fresh air on the cylinder wall (after Equation (11)) corrected.

wobei die Referenz-Temperatur(erhöhung) T_{Luft_Zyl_ref} der Frischluft an der Wand des Zylinders nach Gleichung (11) berechnet wird und die Temperatur(erhöhung) T_{Luft_Zyl} der Frischluft an der Wand des Zylinders nach Gleichung (7) bzw. (8) berechnet wird und somit die Korrektur für die dynamische Temperaturerhöhung der Frischluft aufgrund der dynamischen Temperaturerhöhung der Zylinderwand enthält.Accordingly, in some embodiments, a correction factor is determined: $${\text{FAC}}_{\text{T\_kor}}={\text{T}}_{\text{Luft\_Zyl\_ref}}{\text{/ T}}_{\text{Luft\_Zyl}}$$

wherein the reference temperature (increase) T _{Luft_Zyl_ref of} the fresh air at the wall of the cylinder is calculated according to equation (11), and the temperature (increase) T _{Luft_Zyl of} the fresh air at the wall of the cylinder is calculated according to equation (7) or (8) is and thus contains the correction for the dynamic increase in temperature of the fresh air due to the dynamic increase in temperature of the cylinder wall.

wobei Luftmasse_Kennfeld die oben erwähnte am Prüfstand ermittelte und im Kennfeld abgelegte Frischluftmenge bzw. Frischluftmasse ist und der Korrekturfaktor FAC_{T_kor} nach Gleichung (9) berechnet wird.Then, a corrected amount of fresh air or fresh air mass "air mass _kor " in the cylinder results as follows, wherein here the correction for the dynamic temperature change of the fresh air according to equations (7) or (8) is included: $${\text{air mass}}_{\text{kor}}={\text{air mass}}_{\text{map}}\cdot {\text{FAC}}_{\text{T\_kor}}$$

wherein air mass _{map is} the above-mentioned determined on the test bench and stored in the map fresh air _quantity or fresh air _mass and the correction factor FAC _{T_kor is calculated} according to equation (9).

Thus, in some embodiments, a very simple, but exact correction of the fresh air quantity or fresh air mass, which is stored in the map, taking into account dynamic temperature increases of the cylinder wall and thus the fresh air possible without complex and complex calculations are necessary to the fresh air quantity or To determine fresh air mass.

Some embodiments relate to a controller for an internal combustion engine having at least one cylinder, a draft tube, a port temperature sensor, an intake valve on the cylinder, and an intake port upstream of the intake valve, the controller configured to perform the method described herein. The controller may, for example, be designed as an engine control unit and accordingly have typical elements of an engine control unit, such as one or more processors, a volatile and a non-volatile memory, an interface to a motor coach bus system, etc.

Some embodiments relate to a motor vehicle having such a controller and an internal combustion engine.

• 1 schematisch Verläufe für die Frischlufttemperaturerhöhung veranschaulicht;
• 2 schematisch ein Ausführungsbeispiel einer Verbrennungskraftmaschine eines Kraftfahrzeugs der vorliegenden Erfindung veranschaulicht;
• 3 schematisch ein Ausführungsbeispiel einer Steuerung der Verbrennungskraftmaschine von 1 veranschaulicht; und
• 4 schematisch ein Ausführungsbeispiel eines Verfahrens zur Berechnung einer Frischluftmasse gemäß der vorliegenden Erfindung veranschaulicht.

Embodiments of the invention will now be described by way of example and with reference to the accompanying drawings, in which:

• 1 schematically illustrates curves for the fresh air temperature increase;
• 2 schematically illustrates an embodiment of an internal combustion engine of a motor vehicle of the present invention;
• 3 schematically an embodiment of a control of the internal combustion engine of 1 illustrated; and
• 4 schematically illustrates an embodiment of a method for calculating a fresh air mass according to the present invention.

An embodiment of an internal combustion engine 1 is in 2 schematically illustrates, wherein the internal combustion engine 1 is a gasoline engine and has four cylinders, being in 2 a sectional view of a cylinder 2 the internal combustion engine 1 is illustrated.

The cylinder 2 has an inlet valve 3 , an outlet valve 4 and a combustion chamber 5 that by a cylinder piston 6 can be compressed, as it is known in principle and a cylinder wall 2a , The cylinder wall 2a is the inner wall of the combustion chamber 5 and in the sectional view in 1 is a left and a right side of the cylinder wall 2a shown.

In the combustion chamber 5 , as in 2 illustrated, is typically aspirated fresh air during the intake phase 7 and residual gas 8th that from a previous clock in the combustion chamber 5 remained.

The fresh air 7 is through a suction tube 9 sucked and passes through an inlet channel 10 that is between the inlet valve 3 and the suction tube 9 is arranged through the in 2 open inlet valve 3 in the combustion chamber 5 ,

After combustion, for example, the exhaust gas passes through the opened outlet valve 4 in an exhaust duct 11 as it is well known.

cooling water 12 flows through appropriate cooling water channels, with in 2 , a cooling water channel 13a near the inlet channel 10 and the intake valve 3 shown is a cooling water channel 13b near the exhaust valve 4 and the outlet channel 11 and one cooling water channel each 13c respectively. 13d near the left and right side of the cylinder wall 2a ,

It is also located in the intake manifold 9 just before the inlet channel 10 a temperature sensor 14 for detecting the temperature of the fresh air 7 in the intake manifold 9 ,

The fresh air 7 takes on her way into the cylinder 2 Heat at various points and thus warms, resulting in a temperature increase and a change in density of the fresh air 7 leads.

First, a heat absorption of the fresh air takes place 7 on the in the cylinder 2 in the place of the arrow 15a in the area of the inlet channel 10 in front of the inlet valve 3 , Then there is the inlet valve 3 Heat to the fresh air 7 off (see arrow 15b) and finally there is the cylinder wall 2a Heat to the fresh air 7 off (see arrows 15c and 15d) ,

The temperatures of the contact surfaces at the inlet channel 10 and at the inlet valve 3 are essentially characterized by the cooling water temperature in this embodiment. It changes slowly in time (ie several seconds) and moves when the engine is warm 1 typically in the field 85 - 115 Centigrade.

In contrast, the temperatures of the cylinder inner surfaces (cylinder wall 2a , Piston head, etc.) are strongly influenced by the heat input of the combustion occurred. The heat input due to combustion can be heavily dependent on load and speed and can not even be present in overrun phases (cooling) and can change within a few combustion cycles. Cylinder wall temperatures typically range between 320K-530K with a warm engine 1 ,

3 now shows a control 20 that a procedure 30 which can be explained below 4 is explained in more detail.

The control 20 is as an engine control unit for controlling the internal combustion engine 1 designed and has a processor 21 , a working memory 22 , a read-only memory (or other non-volatile memory) 23 and an interface 24 to a bus system of the motor vehicle (eg, CAN bus or the like) via which it communicates with the internal combustion engine 1 and the temperature sensor 14 is connected so that it data from both the internal combustion engine 1 or relevant data (eg Speed, oil temperature, cooling water temperature, camshaft position, etc.) as well as from the temperature sensor 14 can receive.

In read-only memory 23 For example, data such as maps, characteristics and the like are stored, as well as a program containing commands, so that the controller 20 is capable of the procedure 30 perform.

4 illustrates a flowchart of the method 30 for calculating a fresh air mass in the cylinder 2 the internal combustion engine 1 , The procedure 30 is typically at an operating point of the internal combustion engine 1 executed and for each cylinder of the internal combustion engine 1 in time with the internal combustion engine, so that the associated fresh air mass is available for the respective injection in the cylinder.

For this purpose, first at 31 assuming a steady-state operating state of the internal combustion engine 1 the heating of the fresh air at the inlet channel 10 determined with the aid of equation (3) above at the corresponding current operating point of the internal combustion engine (for example, based on the speed, cooling water temperature, oil temperature, camshaft position, etc.). The controller determines this 20 the effective heat transfer coefficient for the inlet channel on the basis of the map α _w1 , in the read-only memory 23 is stored or determines the effective heat transfer coefficient for the current operating point of the internal combustion engine 1 based on the map. In addition, the controller determines 20 the current temperature T _{EK of} the inlet channel 10 based on the temperature of the cooling water 12 and determines the temperature T _{Luft_Sgr} the fresh air 7 in the intake manifold 9 based on appropriate temperature data, which the controller 20 from the temperature sensor 14 receives, so the current temperature of the fresh air 7 in the intake manifold 9 can be determined.

This gives the controller at 31 the current temperature T _{Luft_v_EV} the fresh air 7 by equation (3) after being in the inlet channel 9 was heated and before further heating through the inlet valve 3 experiences.

In the next step 32 , determines the control 20 a heating of the fresh air at the inlet valve 3 of the cylinder 2 based on the equation (4). For this purpose, the controller takes ( 20 ) the current temperature T _{Luft_v_EV} before the inlet valve 3 as they step in 31 is determined, the current temperature T _{EV of} the intake valve based on the cooling water temperature and determines the effective heat transfer coefficient for the intake valve 3 based on the map α _w2 , in the read-only memory 23 is stored, based on the current operating point of the internal combustion engine 1 ,

This gives the controller at 32 the current temperature T _{Luft_h_EV} the fresh air 7 by means of equation (4) after passing through the inlet valve 3 was heated and with it in the combustion chamber 5 flows.

Finally, the procedure determines 30 at step 33 the warming of the fresh air 7 through the cylinder wall 2a based on equation (5) assuming steady-state operation. The controller takes this 20 the current temperature T _{Luft_h_EV of} the fresh air 7 after passing through the inlet valve 3 was heated and how to step in 32 was determined. In addition, the controller determines 20 the actual effective heat transfer coefficient for the cylinder wall 2a (that is, the wall portion of the combustion chamber 5 ), with which the fresh air 7 comes in contact, based on the current operating point of the internal combustion engine 1 and on the basis of the map α _w3 , which in the read-only memory 23 is stored. As stated above, the temperature T _{Zyl_Wand of} the cylinder wall results from a characteristic map which is also _stored in read-only memory 23 is stored.

This gives the controller 20 at 33 the current (stationary) temperature T _{Luft_Zyl_stationär} the fresh air 7 after passing through the cylinder wall 2a was heated.

In step 34 the current temperature T _{Luft_Zyl_stationär is filtered} by two PT1 filters, so that a temperature T _{Luft_Zyl_PT1 is} obtained, which is a course 102 has, as in 1 is illustrated.

In step 35 determines the control 29 the correction factor T _{Luft_Zyl_kor_dyn} according to equation (6), which takes into account the dynamic change in temperature of the fresh air, by taking the current and filtered temperature T _{Luft_Zyl_PT1} , which they in step 34 multiplied by an effective and dynamic heat transfer coefficient, which it calculates on the basis of the quantity of the corresponding characteristic map incoming fresh air and the speed of the internal combustion engine 1 determined in the read-only memory 23 is stored.

In step 36 determines the control 20 the actual temperature T _{Luft_Zyl} according to equation (7) or (8) by the correction factor T _{Luft_Zyl_kor_dyn} (step 35 ) to the current temperature T _{Luft_Zyl_stationär} (step 33 ) added.

At step 37 determines the control 20 a current reference heating of fresh air in the read-only memory 23 stored reference temperatures of intake, intake port, intake valve and cylinder wall temperature according to equation (9), wherein the calculation at the current operating point of the internal combustion engine 1 he follows. The control 20 So determines a reference temperature for the temperature T _{EK_ref} the inlet channel either based on a stored temperature value or based on a reference temperature of the cooling water. The same applies to the temperature of the fresh air 7 in the intake manifold 9 T _{Luft_Sgr_ref} , for which a stored reference _temperature is taken. The associated effective heat transfer coefficient becomes analogous to step 31 determined.

This gives the controller 20 at 37, a reference _temperature T _{air_v_EV_ref of} the fresh air 7 after passing through the inlet channel 10 was heated at reference conditions.

At step 38 determines the control 20 a current reference heating of the fresh air at the inlet valve 3 of the cylinder 2 according to equation (10). For this purpose, a reference _temperature T _{EV_ref of} the inlet valve is determined, which, for example, in the read-only memory 23 is stored or corresponds to the reference cooling water temperature and in step 37 determined reference _temperature T _{Luft_v_EV_ref} taken. The determination of the associated effective heat transfer coefficient for the heat transfer at the inlet valve is analogous to step 32 ,

This gives the controller 20 at 38, a reference _temperature T _{air_h_EV_ref of} the fresh air 7 after passing through the inlet valve 3 was heated at reference conditions.

At step 39 determines the control 20 a current reference heating of the fresh air on the cylinder wall 2a of the cylinder according to equation (11). For this purpose, a reference _temperature T _{Zyl_Wand_ref of} the cylinder wall is determined, which can either be stored or model-based (or can also be based on the cooling water temperature and can take into account a mass flow of the cooling water), and it becomes the in step 35 determined reference _temperature T _{Luft_h_EV_ref} the fresh air 7 taken after passing through the inlet valve 2 was heated. The associated effective heat transfer coefficient for the transfer of heat from the cylinder wall 2a to the fresh air 7 becomes analogous to step 33 determined.

This gives the controller 20 at 39 the temperature T _{Luft_Zyl_ref of} the fresh air 7 after passing through the cylinder wall 2a was heated.

at 40 determines the control 20 now the correction factor FAC _{T_kor} for the fresh air _mass of the fresh air 7 in the combustion chamber 5 according to equation (12), by taking the ratio of the actual reference temperature (equation (11)) of the fresh air 7 at the current operating point of the internal combustion engine 1 and the corresponding actual temperature (Equation (7) or (8)) calculated according to T _{Luft_Zyl_ref} / T _{Luft_Zyl} .

at 41 determines the control 20 now at the current operating point of the internal combustion engine 1 the current fresh air mass air mass _cor according to equation (13), by one of the read-only memory 23 stored map determines a fresh air mass air mass _map , which was determined on a test bench, and this fresh air mass with the correction factor FAC _{T_kor} , in step 40 was determined multiplied.

This gives the controller 20 at step 41 the corrected fresh air mass air mass _cor , in which (also) the dynamic heating of the fresh air sucked in 7 through the cylinder wall 2a is taken into account.

LIST OF REFERENCE NUMBERS

1

Internal combustion engine

2

cylinder

2a

cylinder wall

3

intake valve

4

outlet valve

5

combustion chamber

6

cylinder piston

7

fresh air

8th

residual gas

9

suction tube

10

inlet channel

11

exhaust port

12

cooling water

13a-d

Cooling water passages

14

temperature sensor

15a-c

Arrows (heat absorption)

20

control

21

processor

22

random access memory

23

Only memory

24

interface

30

Method for calculating fresh air mass in a cylinder

31

Determining a warming of the fresh air in the inlet channel to the cylinder

32

Determine warming at the inlet valve

33

Determine heating on cylinder wall (stationary)

34

Filter of stationary heating cylinder wall

35

Determine correction factor for dynamic temperature increase

36

Determine warming of the fresh air including consideration of dynamic temperature increase

37

Determine reference heating of the fresh air in the inlet duct to the cylinder

38

Determine reference heating at inlet valve

39

Determine reference heating to cylinder wall

40

Determine correction factor

41

Determine corrected fresh air mass

100

Temperature curve of the fresh air assuming a constant cylinder wall temperature

101

Theoretical temperature profile of the fresh air

102

Temperature profile of the fresh air by using two PT1 filters

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 10158261 A1 [0003]

Claims (15)

Method for calculating a fresh air mass in a cylinder (2) of an internal combustion engine (1), comprising: Determining (36) a heating of the fresh air (7) on a wall (2a) of the cylinder (2), wherein the temperature of the wall (2a) of the cylinder changes dynamically; and Calculating (41) the fresh air mass of the fresh air (7) in the cylinder (2) based on the determined heating of the fresh air mass. Method according to Claim 1 wherein determining the heating of the fresh air (7) comprises determining the heating of the fresh air (7) assuming a constant temperature of the wall (2a) of the cylinder. Method according to Claim 2 wherein the determined heating of the fresh air (7) is filtered by a filter assuming a constant temperature of the wall (2a) of the cylinder to determine a dynamic correction of the heating of the fresh air (7) on the wall (2a) of the cylinder. Method according to Claim 3 wherein the filter comprises at least one PT1 filter. Method according to Claim 4 wherein the filter comprises two series-connected PT1 filters. Method according to Claim 4 or 5 , where the filter is determined empirically. Method according to one of Claims 3 to 6 wherein the filter depends on at least one parameter characteristic of the temperature of the wall (2a) of the cylinder (2). Method according to Claim 7 wherein the parameter represents a quantity of heat introduced during the combustion, a speed of the internal combustion engine and / or a heat transfer of cooling water to the wall (2a) of the cylinder (2). Method according to one of Claim 3 to 8th wherein the filtered heating is multiplied by an effective and dynamic heat transfer coefficient. Method according to Claim 9 , wherein the effective and dynamic heat transfer coefficient of a speed of the internal combustion engine and / or an intake manifold pressure depends. Method according to Claim 10 , wherein the effective and dynamic heat transfer coefficient is determined empirically. Method according to the Claims 2 and 3 and one of the Claims 4 to 11 wherein determining (36) the heating of the fresh air (7) on the wall (2a) of the cylinder (2), wherein the temperature of the wall (2a) of the cylinder changes dynamically, the addition from the determined heating of the fresh air (7 ) assuming a constant temperature of the wall (2a) of the cylinder and the dynamic correction of the heating of the fresh air (7) on the wall (2a) of the cylinder. Method according to one of the preceding claims, further comprising determining (39) reference heating of the fresh air (7) of the wall (2a) of the cylinder (2) based on at least one reference parameter. Method according to Claim 13 wherein the fresh air mass of the fresh air (7) in the cylinder (2) is calculated based on the determined heating of the fresh air mass and the determined reference heating. Control for an internal combustion engine (1) comprising at least one cylinder (2), a suction pipe (9), a suction pipe temperature sensor (14), an inlet valve (3) on the cylinder (2) and an inlet channel (10) in front of the inlet valve (3) , wherein the controller (20) is adapted to carry out the method according to one of the preceding claims.

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