DE102004035317A1 - Method and device for controlling an internal combustion engine - Google Patents

Abstract

An apparatus and a method for controlling an internal combustion engine are described. A first actuator is used to influence the fresh air mass flow supplied to the internal combustion engine and / or the exhaust gas recirculation mass flow. Based on a comparison between a desired value and an actual value for the fresh air mass flow and / or the exhaust gas recirculation mass flow, at least one manipulated variable for the at least one actuator can be predetermined by means of a controller. The at least one manipulated variable is superimposed on a model-based precontrol value.

Description

The The invention relates to a method and a device for controlling an internal combustion engine.

A method and a device for controlling an internal combustion engine is, for example, from DE 196 20 039 known. In the system described therein, a first actuator is used to influence the fresh air mass flow supplied to the internal combustion engine and a second actuator to influence the exhaust gas recirculation mass flow. As a first actuator, a control valve is preferably used, which is arranged in the intake pipe to the compressor. The second actuator is preferably an exhaust gas recirculation valve, which is arranged in the exhaust gas recirculation line.

In certain operating conditions is an accurate setting of both the fresh air mass flow as also the proportion of recirculated exhaust gas required. To do this both the exhaust gas recirculation valve operated as well as the control flap. Such a Operating state, for example, in the regeneration of a Exhaust after-treatment system before, for example, during regeneration a NOx storage catalyst.

Usually there is a regulation of the intake manifold pressure, that is the pressure before the intake into the internal combustion engine. The regulation of intake manifold pressure via the Exhaust gas recirculation valve based on the assumption that the intake manifold pressure is independent of the position of the butterfly valve always increases when the exhaust gas recirculation valve continues to open. But this only applies if the control flap is set so far that sets a significant pressure drop across the control valve. From a certain opening angle However, the damper can reverse this effect. Is in In this case, the exhaust gas recirculation valve open, flows more exhaust over the Exhaust gas recirculation line and therefore less mass flow over the turbine. For this reason promotes the compressor less and the pressure after compressor is smaller. This in turn causes the intake manifold pressure to drop. Summarized This means that the sense of control of intake manifold pressure control by means of the exhaust gas recirculation valve depending on the opening angle change the control flap can. This behavior can not be compensated by the controller and thus also do not adjust the setpoint.

At usual Regulator structures must always be between a good one in the application leadership and a good interference behavior be weighed. By having a first adjuster to influence of the internal combustion engine supplied fresh air mass flow and / or the exhaust gas recirculation mass flow is provided, starting from a comparison between a Setpoint and an actual value for the fresh air mass flow and / or the exhaust gas recirculation mass flow by means of a Regulator at least one manipulated variable for the at least one Steller is specifiable, and that the at least one manipulated variable a model-based Precontrol value superimposed the controller only needs to compensate for small deviations. D. H. the controller can be good at disturbing behavior be applied.

Especially It is advantageous if a first actuator, that of the internal combustion engine supplied fresh air mass flow influenced, and a second actuator, the exhaust gas recirculation mass flow are provided, based on a comparison between a first set value and a first actual value for the fresh air mass flow a first manipulated variable for the first Steller and that starting from a comparison between a second Setpoint and a second actual value for the fresh air mass flow a second manipulated variable for the second Steller is specifiable, and that at least one manipulated variable is a model-based Precontrol value superimposed becomes. This means, that in each case a regulator for the fresh air mass flow and a regulator for the exhaust gas recirculation mass flow are provided and at least one of the controller additionally one Precontrol is assigned.

Thereby, that the precontrol value can be predetermined by means of a model can the pre-control value can be specified very precisely.

Especially It is advantageous if the model has at least a first partial model for one Mixing point and / or a second part model for the controller includes. When Mixing point is the space between the inlet of the combustion engine and the two writers referred. The writers are preferably around the control flap and the exhaust gas recirculation valve. By dividing the model, the adaptation of the model becomes clear simplified.

Especially It is advantageous if the first part model for the mixer plate the temperature T3 after the exhaust of the internal combustion engine, the temperature T21 before the actuator, the speed N, the setpoints for fresh air mass flow and Exhaust gas recirculation mass flow processed. These sizes work significantly on pre-tax values. To increase the accuracy can still other sizes considered become.

It is advantageous if the second submodel processes for predetermining the manipulated variable for the fresh air mass flow as input variables at least one pressure P22 in the intake manifold and the setpoint value for fresh air mass flow. These sizes do not work significantly to the pre-tax value. To increase the accuracy even more sizes can be considered.

It is particularly advantageous if the second submodel ( 235 ) to specify the manipulated variable for the fresh air mass flow as input variables at least T21 temperature and / or a pressure P21 before the actuator and after the compressor and / or a target mass air flow MA processed. These quantities have a significant effect on the pre-tax value. To increase the accuracy even more sizes can be considered.

It is particularly advantageous if the second part model 335 for the specification of the manipulated variable for the exhaust gas recirculation mass flow as input variables at least one temperature T3 and / or a pressure P3 of the exhaust gas to the outlet of the internal combustion engine and processed before the turbine and / or a target exhaust gas mass flow MR. These quantities have a significant effect on the pre-tax value. To increase the accuracy even more sizes can be considered.

Thereby that the setpoint is adapted to the temporal behavior of the control loop is, the behavior of the controller and the feedforward control can be clearly be improved.

Thereby that the actual value can be predetermined by means of a second model can be cost-intensive sensors to save the actual value.

Thereby, that the controller can be switched off in certain operating states is improved the behavior of the system is clear.

drawing

The Invention will be described below with reference to the drawing Embodiments explained. It shows

1 a block diagram of an internal combustion engine and

2 a block diagram of the procedure according to the invention.

in the The following is the procedure according to the invention described using the example of a control flap and an exhaust gas recirculation valve. In principle the procedure according to the invention applicable to all actuators with which the fresh air mass flow or the exhaust gas recirculation mass flow can be influenced. Instead of the fresh air mass flow or the exhaust gas recirculation mass flow can also other sizes that correspond to these sizes, be controlled and / or controlled. Ie. at the setpoints or the actual values are quantities that represent the fresh air mass flow or the exhaust gas recirculation mass flow characterize. The manipulated variables are suitable Sizes to Control of the corresponding actuator.

in the The following is the procedure according to the invention described using the example of a diesel internal combustion engine. The invention but is not limited to the application to diesel engines, they can also be used in other internal combustion engines, especially direct-injection gasoline engines be used.

An internal combustion engine 100 is via a high pressure fresh air line 102 a certain amount of gas ML22, which contains a certain oxygen content MO22 supplied. The size MO22 is also called oxygen content before combustion. The high pressure fresh air line 102 consists of two parts. A first part is with 102 a second is with 102b designated. The first part corresponds to the line up to Abgaszumischung. The second part 102b corresponds to the line after Abgaszumischung. In the first part 102 is a control flap 104 arranged. The air in the first part of the high pressure fresh air line 102 has a temperature T2 and a pressure P2. Through this part of the high pressure fresh air line or through the control valve flows the fresh air mass flow MA.

About a low pressure fresh air line 108 the ambient air reaches a compressor 106 and then flows over the control flap 104 in the high pressure fresh air line 102 , The volume of air ML21 with the oxygen content MO21 flows into the high pressure fresh air line via the compressor 102 , The air volume ML21 with the oxygen content MO21, through the low pressure fresh air line 108 flows in the static state corresponds to the amount of air with the corresponding amount of oxygen passing through the compressor 106 or through the control flap 104 flows. Between the compressor 106 and the control valve prevails the pressure P21 and the temperature T21.

The temperature T1 and the pressure P1, in the low pressure fresh air line 108 prevails corresponds to the ambient conditions, ie the ambient pressure and the ambient temperature.

From the internal combustion engine 100 the quantity of air ML31 with the oxygen content MO31 flows into a high-pressure exhaust gas line 110 , The size MO31 is also called oxygen content after combustion. In the high-pressure exhaust gas line 110 the temperature T3 and the pressure P3 prevails. These Values are also referred to as exhaust gas pressure P3 and exhaust gas temperature T3.

An air volume ML32 comes from the high-pressure exhaust line 110 to a turbine 112 , this is also referred to as the amount of air through the turbine. From the turbine 112 the exhaust gas enters a low-pressure exhaust gas line 114 which also serves as an exhaust pipe 114 referred to as. In the low-pressure exhaust line, temperature T4 and pressure P4 prevail.

The turbine 112 drives over a wave 111 the compressor 106 at. The speed NL of the shaft is called the supercharger speed. By means of a loader actuator 113 The characteristics of the turbine and thus of the entire loader can be influenced. To control the loader 113 subjected to a drive signal LTV, which has an adjustment of the loader by a stroke LH result. The size LH is also referred to as loader stroke and the size LTV as Ladertastverhältnis.

Between the high pressure exhaust gas line 110 and the high pressure fresh air line 102 there is a connection as the exhaust gas recirculation line 116 is designated. Through this exhaust gas recirculation line 116 flows the amount of air MR, which includes the oxygen content MOA. The cross section of the exhaust gas recirculation line 116 is preferably by means of an exhaust gas recirculation valve 118 controllable. To control the exhaust gas recirculation actuator 119 a control signal ATV is applied, which is an adjustment of the exhaust gas recirculation valve 118 results in a stroke AH. The quantity AH is also referred to as the exhaust gas recirculation stroke and the quantity ATV as the exhaust gas recirculation duty cycle.

Preferably, the rotational speed N at the crankshaft and / or the camshaft of the internal combustion engine by means of a speed sensor 101 detected. Furthermore, quantity actuators 103 provided, which determine the fuel quantity to be injected ME, which is supplied to the internal combustion engine. For this purpose, the actuators 103 subjected to a quantity signal ME.

In 2 the procedure according to the invention is illustrated by means of a block diagram. An actual value determination 200 determined based on various inputs, not shown, an actual value for the fresh air mass flow. In a simple embodiment, it is provided that the actual value determination 200 is designed as a sensor that detects the fresh air mass flow immediately. In an improved embodiment, it is provided that a model calculation is used for actual value determination, for example, in the DE 199 63 358 is described. There the fresh air mass flow corresponds to the size ML21.

The output signal of the actual value determination 200 passes through a node 205 to a controller 220 , With the output signal of the controller 220 becomes a node 225 applied, in turn, the control valve 104 subjected to a manipulated variable. At the second input of the connection point 205 is the negative signal of the output signal of a setpoint filter 210 , in turn, as the input, the output signal of a setpoint input 215 is supplied. The setpoint specification 215 Specifies the desired setpoint for the fresh air mass flow MA depending on various operating parameters and different operating states. The output signal of the setpoint filter 210 also gets to a model 230 the mixing point. The model 230 also processes the output of various sensors 232 which detect signals relating to the temperature T3 between the engine exhaust and the turbine input, the temperature T21 between the compressor outlet and the control valve, and the engine speed N. In addition to these sensors, further sensor signals can be detected and detected by the model 230 be evaluated.

With the output of the model 230 becomes an inverse model 235 the control flap applied. The model 230 provides signals relating to the fresh air mass flow MA and the pressure P22, which corresponds to the pressure before the intake of the internal combustion engine, to the inverse model 235 , Further, the inverse model 235 the signals of different sensors 240 representing the pressure P21 and the temperature T21 between the outlet of the compressor and the control valve 104 characterize, fed. Instead of the sensors 240 It is also possible to provide a model which determines these variables on the basis of other variables. About a characteristic 245 gets the output of the inverse model 235 to the connection point 225 , The model 230 , in conjunction with the inverse model 235 and the characteristic 245 act as pilot control for the manipulated variable of the control flap 104 ,

A parallel branch for the regulation of the exhaust gas recirculation mass flow MR is designated by corresponding reference symbols. The exhaust gas recirculation valve 118 becomes the output of a node 325 fed, at one input, the output signal of a controller 320 pending. The regulator 320 becomes the output signal of the node 305 fed, in turn, as input the output signal of an actual value determination 300 is supplied. The actual value determination 300 is designed similar to the actual value determination 200 ie it can be designed as a sensor or as a model. The setpoint specification 315 specifies a setpoint value for the exhaust gas recirculation mass flow, which is transmitted via a setpoint filter 310 also to the connection point 305 or to the model 230 arrives. Instead of the exhaust gas recirculation mass flow and the exhaust gas recirculation rate can be specified as the desired value. The model 230 impinges on a second inverse model 335 with a signal characterizing the exhaust gas recirculation mass flow MR and the pressure P22 before the intake of the internal combustion engine. Furthermore, the inverse model processes 335 Signals from sensors 340 , in particular the pressure P3 and the temperature T3 between the outlet of the internal combustion engine and the input of the turbine. Instead of the sensors 340 It is also possible to provide a model which determines these variables on the basis of other variables. Over a second characteristic 345 passes the output of the second inverse model 335 to the node 325 ,

The regulator 220 regulates the fresh air mass flow MA to that of the setpoint specification 215 specified setpoint. For this purpose, the actual value of the actual value determination 200 is compared with the filtered setpoint. Based on the deviation of the setpoint from the actual value then the manipulated variable for acting on the control valve 104 from the regulator 220 specified. The actual value determination 200 can be used as a sensor that determines the fresh air mass flow directly, or as a model, as for example from the DE 199 63 358 is known to be trained.

This control is superimposed on a feedforward control. The feedforward control essentially contains a model which, based on the setpoint value for the fresh air mass, contains a manipulated variable for the control flap 104 pretends. The model includes at least two partial models. A partial model 230 simulates the mixing point, ie the area between the exhaust gas recirculation valve, the control flap 104 and the inlet of the internal combustion engine. Another submodel 235 includes an inverse model of the control flap 104 , By means of the characteristic 245 This output signal of the model, which corresponds to the desired effective flow area of the control flap, into a control variable for the control valve 104 implemented.

This means the feedforward calculated based on the setpoint for the Fresh air mass MA and various operating characteristics, in particular Temperature and pressure sizes, one desired flowed through effectively area the butterfly valve and thus a pre-tax value. The regulation is calculated starting from the deviation of the setpoint from the actual value of the fresh air mass also a manipulated variable for the control flap. These two sizes will be in the connection point preferably additive to the formation of the manipulated variable superimposed.

A corresponding control circuit with a pilot control is also provided for the exhaust gas recirculation mass flow MR. Here is the setpoint specification 315 a corresponding setpoint in the filter 310 filtered and in the connection point 305 with the actual value of the actual value determination 300 is compared. As actual value determination 300 Preferably, a sensor is also used, which detects the exhaust gas recirculation mass flow immediately. Since such sensors are usually very expensive and expensive and are not available at low cost, a model corresponding to the actual value determination model is also used here in a preferred embodiment, which determines these variables on the basis of further operating parameters. Depending on the deviation between the setpoint and the actual value, the controller calculates 320 the manipulated variable for controlling the exhaust gas recirculation valve 118 ,

Further a feedforward control is provided, which starts from the setpoint likewise predetermines a pilot control value by means of a model. The Model includes the first submodel modeling the mixing point, and an inverse model of the exhaust gas recirculation valve. The model is closing a characteristic.

This means starting from a comparison between a first setpoint, which characterizes the fresh air mass flow and a first actual value, becomes a manipulated variable for the first actuator, which is preferably designed as a control flap, given. Further is based on the comparison between a second setpoint, the exhaust gas recirculation mass flow characterized and a second actual value is a manipulated variable for the second actuator, which is preferably designed as an exhaust gas recirculation valve is, given.

D. H. it is provided a parallel structure, in each case one Setpoint for the fresh air mass flow or a target value for the exhaust gas recirculation mass flow is adjusted to the predetermined setpoint. In a preferred Design is provided that the manipulated variable, the the control is determined, a pilot value is superimposed. Is preferred provided that used to form the pilot value of the setpoint which is also fed to the control loop. For the formation of pre-tax values a model is used that has at least a first or a second one Partial model that models or merges the mixing point represent an inverse model of the actuator. Accordingly is at a provided particularly advantageous embodiment that the actual value determination is also designed as a model, starting the actual value determined by various operating parameters.

Preferably, the target value of the exhaust gas recirculation mass flow, ie the mass flow that flows through the exhaust gas recirculation valve, set as the setpoint and the actual value adjusted to this predetermined setpoint. Alternatively, as the setpoint, the Exhaust gas recirculation rate specified and adjusted to the setpoint.

Advantageous is that for the fresh air mass flow and for the exhaust gas recirculation mass flow in each case a control circuit is provided, this control circuit for One includes a controller and the other a feedforward control. Ie. the two sizes will be independently each adjusted to a desired value.

According to the pilot control is designed such that they predetermine the time courses of the manipulated variable for the control flap and the exhaust gas recirculation valve so that the system alone is able to follow the setpoint changes by means of this precontrol. Ie. in extreme cases, can on the regulator 220 and 320 be completely dispensed with or he can be turned off in certain operating conditions. The model with which the setpoint is converted into the manipulated variable contributes significantly to the success of feedforward control. The model includes a model for the mixing point of fresh air and exhaust gas recirculation, which is considered to be a vessel with volume V22 and pressure P22. Furthermore, partial models are provided, which map the exhaust gas recirculation valve and the control valve as chokes. The main input variables for these models are the pressure P3 after the engine outlet and upstream of the turbine, the pressure P21 upstream of the control valve and downstream of the compressor the pressure P22 in the intake manifold, ie between the engine inlet and the exhaust gas recirculation valve or control damper. the temperature T3 after the outlet of the internal combustion engine, the target value for the exhaust gas recirculation rate or the exhaust gas recirculation mass flow and in the setpoint for the air mass flow.

The quantities P3, P21, P22, T21 and T3 can either be measured directly with sensors or calculated by means of a model on the basis of other operating parameters. As a model is preferably a in the DE 199 63 358 described model. The target values MR and MA for the exhaust gas recirculation rate and for the air mass flow used by the model are preferably the same reference values which are also supplied to the control. On the basis of these input variables, the model provides temporal profiles for surfaces of the control valves and / or the exhaust gas recirculation valve that are effectively flowed through. These are about characteristics 245 respectively. 345 or more complex dynamic models in control variables for the control flap and / or the exhaust gas recirculation valve shown.

The setpoint specification 215 respectively. 315 Specifies the setpoint for the corresponding manipulated variable depending on various operating parameters and operating states. When changing an operating variable or when switching to another operating state, a discontinuous course of the setpoint generally results. Such a discontinuous or sudden course of the desired value, the corresponding size usually can not follow. This leads to a control deviation that the controller tries to correct. Overall, this leads to an undesirable behavior of the controller. Therefore, the invention provides that the setpoint filter 210 respectively. 310 to filter the setpoint input in such a way that there is a steady course of the setpoint value and that the overall system can follow these specifications at all times. Ie. The time behavior of the setpoint is adjusted by the setpoint filter to the temporal behavior of the overall system or to the temporal behavior of the manipulated variable. Ie. the setpoint filter 210 respectively. 310 generates a dynamically smoothed course of the setpoint. Furthermore, the filter provides the time derivative of this size.

The model 230 calculates the desired fresh air mass flow from various input variables as well as the pressure P22 in the intake manifold. The models used as input variables 230 the temperature T3, the temperature T21 in front of the control flap, the dynamically ground target air mass flow, the time derivative of the dynamically ground target air mass flow, the dynamically attenuated exhaust gas recirculation rate, the time derivative of the dynamically attenuated exhaust gas recirculation rate and the engine speed. Based on these sizes, the model calculates 230 the desired air mass flow ML via the control valve 104 , the target exhaust gas mass flow via the exhaust gas recirculation valve and the setpoint pressure P22 in the mixing tank.

The inverse models 235 and 335 calculate from the desired mass flow desired to flow through the throttle, the effective flow area of the respective throttle. For this purpose, the pressure and / or the temperature before the throttle and the pressure and / or the temperature after the throttle is used. The input variables for the model 245 the control damper is the pressure P21 in front of the damper and after the compressor, the pressure P22 in the intake manifold and the temperature T21 in front of the damper. The input variables of the model 335 the exhaust gas recirculation valve 118 are the pressure P3 after the exhaust of the internal combustion engine and in front of the turbine, the pressure P22 in the intake manifold, the temperature T3 after the exhaust of the internal combustion engine and the target exhaust gas mass flow MR, passing through the exhaust gas recirculation valve 118 should flow.

The setpoints for the effective flow areas for the control flap and the exhaust gas recirculation valve are on the characteristics 245 and 345 converted into manipulated variables for the control flap and the exhaust gas recirculation valve. Instead of the characteristic, more complex dynamic models can be used be used.

The feedforward results in the advantage that it is possible to react very quickly to changes in the desired value, ie, a very rapid guiding behavior results. Here, the system dynamics is already taken into account. This means that both the exhaust gas recirculation rate or exhaust gas recirculation mass flow and the air mass flow can be adapted very quickly to changing conditions by the precontrol. This is particularly advantageous when switching between different operating states such as in the regeneration mode or from the regeneration operation out. Since the two control loops are independent of each other and there is no feedback at all in a system without control, there are no stability problems with this structure. If an additional controller is used, it must only correct disturbing influences and model inaccuracies, as the guiding behavior is ensured by the feedforward control. The coupling of the two actuators is above the model of the mixing point 230 displayed. Ie. the controllers are decoupled, which greatly simplifies the application.

It is particularly advantageous if, in certain operating states, only the pilot control is active and the control is dispensed with, ie that the control is switched off. This is done for example by the fact that in the presence of certain operating conditions, the connection between controller 220 and the link point 225 or between the controller 320 and the link point 325 is interrupted by a switching means. Such an operating state is present, for example, if a small control deviation results in a large manipulated variable change. In such operating states, there is a low sensitivity between the manipulated variable and the size to be regulated. In these operating states, the control is then dispensed with and only the pilot control values are used to control the actuator. This protects the actuator and prevents interference. This can also be advantageous in terms of tolerances.

At the Example of the control of the air mass by means of a control flap in Regeneration mode means the following: The influence of the damper position in the wide open Range of damper on the air mass is practically invisible. Would with Help of a scheme tries to set a setpoint in this non-sensitive To regulate area, so would the controller caused by the measurement noise large fluctuations in the manipulated variable, the control flap unnecessary could burden. When using a model-based feedforward is in such non-sensitive areas shut off the scheme. The feedforward control provides a much quieter in the field of low sensitivity Manipulated variable as a regulator. This protects the mechanics of the controller and Disturbing influences avoided the air system.

Usually, as a regulator 220 respectively. 320 a controller is used, which in particular has PI behavior. The I component builds up essentially in proportion to the signed area between the setpoint and the actual value. If an erratic course is specified for the manipulated variable, the result is a time-delayed change of the actual value to be regulated due to the distance and actuator dynamics. For this reason, erratic setpoint value curves lead to a non-physical structure of the I component. To reduce this again, the controller must in the corresponding other direction with respect to the setpoint undershoot or overshoot. This behavior leads to poor control behavior and can only be mitigated by corresponding values for the control parameters. With corresponding control parameters, however, again results in a poor leadership behavior.

According to the invention it is provided that by the setpoint filter 210 and 310 this effect can be significantly reduced. This is achieved by using the setpoint filter 210 respectively. 310 the course of the setpoint is adapted to the controlled system and / or actuator dynamics. This is achieved by filtering the setpoint such that it has the same or at least a similar temporal behavior as the controller and / or the entire controlled system. If the actuator has PT1 behavior, for example, a filter with PT1 behavior is used. As a result, the relevant area for the build-up of the I component significantly reduced. Now, the controller can be designed with a larger AI, as the unwanted build-up of the I component is avoided.

According to the invention, the setpoint filter 210 and 310 configured such that a dynamic adaptation of the setpoints takes place on the track behavior. From this adjusted course of the setpoint values, an effectively flowed through target area is calculated. This quantity is used both to calculate the pilot control values by the model 230 and the models 235 and 335 used as well as a target size for the scheme 210 respectively. 320 , The calculation of the control deviation is the non-modeled residual dynamics, z. B. actuator dynamics of this manipulated variable over a dead time and a PT1 member shown. By this measure, the controller must 220 respectively. 320 only compensate for model inaccuracies and disturbances and can be designed accordingly for speed.

If large control deviations occur in the case of a controller which has at least one integral behavior, this leads, in the case of control parameters, to the are necessary for a good dynamic behavior, to large values of the integral part. These large values cause overshoots or undershoots. This behavior is not desired. If corresponding values are selected for the control parameters in which no overshoot or undershoot occur, this leads to a poor dynamic behavior, that is, the actual value only slowly reaches the corresponding setpoint.

In order to avoid this, it is provided in a particularly advantageous embodiment that the amount of control deviation, that is, at the point of connection 205 and / or at the point of connection 305 pending signal is limited by means of a limiter to a maximum value.

Claims (11)

Method for controlling an internal combustion engine with at least a first actuator for influencing the internal combustion engine supplied fresh air mass flow and / or the exhaust gas recirculation mass flow, starting from a comparison between a setpoint and an actual value for the fresh air mass flow and / or the exhaust gas recirculation mass flow by means of a Regulator at least one manipulated variable for the at least a controller is specifiable, wherein the at least one manipulated variable is a model-based Precontrol value superimposed becomes. Method according to claim 1, characterized in that that the precontrol value can be predetermined by means of a model. Method according to claim 2, characterized in that that the model at least a first sub-model for a mixing point and / or a second partial model for the actuator. Method according to claim 3, characterized that the first submodel for the mixer plates the temperature T3 after the outlet of the internal combustion engine, the temperature T21 in front of the actuator, the speed N, the setpoints for fresh air mass flow and the exhaust gas recirculation mass flow processed. Method according to claim 3, characterized that the second part model for the specification of the manipulated variable for the fresh air mass flow as input variables at least processed a pressure P22 in the intake manifold and the setpoint for fresh air mass flow. Method according to claim 3, characterized in that the second partial model ( 335 ) to specify the manipulated variable for the fresh air mass flow as input variables at least T21 temperature and / or a pressure P21 before the actuator and after the compressor and / or a target mass air flow MA processed. Method according to claim 3, characterized that the second partial model for the specification of the manipulated variable for the exhaust gas recirculation mass flow as input variables at least a temperature T3 and / or a pressure P3 of the exhaust gas to the outlet of Internal combustion engine and before the turbine and / or a target exhaust gas mass flow MR processed. Method according to claim 1, characterized in that that the setpoint is adapted to the temporal behavior of the control loop becomes. Method according to claim 1, characterized in that that the actual value can be predetermined by means of a second model. Method according to claim 1, characterized in that that the controller can be switched off in certain operating states. Device for controlling an internal combustion engine with at least a first actuator for influencing the internal combustion engine supplied Fresh air mass flow and / or the exhaust gas recirculation mass flow, with a controller based on a comparison between a setpoint and a Actual value for the fresh air mass flow and / or the exhaust gas recirculation mass flow by means of a at least one manipulated variable for the at least one Steller pretends, and means, the at least one manipulated variable a model-based Override precontrol value.