CN1724858A - The method and apparatus of controlling combustion engine - Google Patents

Abstract

A method and apparatus for controlling an internal combustion engine. The first regulator serves to influence the fresh air flow to the internal combustion engine. The second regulator is used to influence the exhaust gas recirculation flow. From the comparison between the first setpoint value and the first actual value of the fresh air flow, the value of the first control parameter of the first controller can be predetermined, from the second setpoint value and the second actual value of the exhaust air flow. Based on the comparison between the values, the value of the second control parameter of the second controller can be predetermined.

Description

Method and device for controlling an internal combustion engine

technical field

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

Background technique

A method and a device for controlling an internal combustion engine are known, for example, from DE19620039. In the system described in this document, a first regulator is used to influence the fresh air flow to the internal combustion engine, while a second regulator is used to influence the exhaust gas recirculation flow. In particular, a regulating valve arranged in the intake line downstream of the compressor is used as the first regulator. An exhaust gas recirculation valve arranged in the exhaust gas recirculation line is used as a second regulator.

Under certain operating conditions, not only the fresh air flow but also the portion of the recirculated exhaust air needs to be precisely adjusted. For this purpose, both the exhaust gas recirculation valve and the control valve must be operated in a controlled state. Such an operating state exists, for example, during regeneration of an exhaust gas aftertreatment system, for example during regeneration of a nitrogen oxide storage vehicle exhaust gas purifier.

Usually the intake manifold pressure, ie the pressure before entering the intake port of the internal combustion engine, is regulated. The regulation of the intake manifold pressure via the exhaust gas recirculation valve is based on the assumption that the intake manifold pressure does not always increase depending on the position of the control valve while the exhaust gas recirculation valve is still open. However, this only applies when the control valve is opened until a significant pressure difference across the control valve occurs. However, this effect may be reversed from a certain regulating valve opening. When the EGR valve is opened in this situation, more exhaust gas flows through the EGR line and therefore less flow through the turbine. For this reason the compressor delivers less and the pressure after the compressor becomes smaller. It again leads to a reduction in intake pipe pressure. All in all this means that with the aid of the exhaust gas recirculation valve, the control meaning of the intake manifold pressure control depending on the opening of the control valve can be changed. This characteristic cannot be compensated by the regulator and therefore the setpoint cannot be adjusted.

Contents of the invention

Since a first regulator is provided which influences the flow of fresh air supplied to the internal combustion engine, and a second regulator influences the flow of exhaust gas recirculation, wherein the comparison between the first target value and the first actual value for the fresh air flow Proceedingly, a first control parameter can be predetermined for the first controller, and a second controller can be predetermined for the second controller starting from a comparison between a second setpoint value and a second actual value for the fresh air flow. Two adjustment parameters, so the adjustment process can be significantly improved. By means of this arrangement, a reversal in regulation can be avoided. That is to say, the exhaust gas recirculation valve has the same direction of adjustment regardless of the position of the control valve. In addition, the use is significantly simplified, since until now the exhaust gas recirculation rate had to be used indirectly via the intake manifold pressure. The exhaust gas recirculation rate can now be predetermined directly as a target value.

It is particularly advantageous if there is a first controller for influencing the flow of fresh air supplied to the internal combustion engine, and a second controller for influencing the flow of exhaust gas recirculation, wherein from a first target value and a first actual value for the fresh air flow Starting from a comparison between the first controller, a first control parameter can be predetermined, starting from the comparison between the second target value for the fresh air flow and the second actual value, the second controller can be given A second control variable is predetermined, and at least one control variable is superimposed on the model-based pilot control value. That is to say, a fresh air flow regulator and an exhaust gas recirculation flow regulator are respectively provided, and at least one of the controllers is additionally assigned a pre-control. Since the pilot control value can be predetermined by means of the model, the pilot control value can be predetermined very precisely.

It is particularly advantageous if the model contains at least one first submodel for the hybrid position and/or a second submodel for the controller. The space between the input of the internal combustion engine and the two regulators is called the mixing position. Regulators are in particular regulating valves and exhaust gas recirculation valves. Through the distribution of the models, the fitting of the models is significantly simplified.

It is particularly advantageous if the first submodel of the hybrid controller processes the target values for the temperature T3 downstream of the exhaust port of the internal combustion engine, the temperature T21 upstream of the controller, the rotational speed N, the fresh air flow and the exhaust gas recirculation flow. These parameter values mainly have an effect on the precontrol values. Other parameter values can also be considered in order to increase the accuracy.

Preferably, the second sub-model for predetermining the control variable of the fresh air flow as an input variable processes at least the desired value of the pressure P22 in the intake manifold and of the fresh air flow. These parameter values mainly have an effect on the precontrol values. Other parameter values can also be considered in order to increase the accuracy.

Particularly preferably, the second submodel (235) for predetermining the control parameters of the fresh air flow as an input parameter at least processes the temperature T21 and/or the pressure P21 before the regulator and after the compressor, and /or rated air flow MA. These parameter values mainly have an effect on the precontrol values. Other parameter values can also be considered in order to increase the accuracy.

Particularly preferably, the second submodel ( 235 ) for predetermining the control parameters of the exhaust gas recirculation flow as an input parameter treats at least the exhaust gas temperature T3 and/or the pressure after the output of the internal combustion engine and before the turbine P3, and/or rated exhaust gas flow rate MR. Importantly, these parameter values have an effect on the precontrol values. Other parameter values can also be considered in order to increase the accuracy.

The behavior of the regulator and pre-controller is significantly improved due to the adaptation of the nominal value to the time behavior of the regulating circuit.

Since the actual value can be predetermined by means of the second model, expensive sensors for determining the actual value can be dispensed with.

Since the controller can be switched off in certain operating states, the system behavior is significantly improved.

Description of drawings

The invention is explained below with the aid of the embodiments shown in the drawings.

Figure 1 shows a block diagram of an internal combustion engine while

Shown in Figure 2 is a block diagram of an approach in accordance with the present invention.

Detailed ways

In the following, the procedure according to the invention will be described using the example of a control valve and an exhaust gas recirculation valve. In principle, the approach according to the invention is suitable for all regulators which can influence the fresh air flow or the exhaust gas recirculation flow. Instead of the fresh air flow or the exhaust gas recirculation flow, other parameter values corresponding to these quantities can also be adjusted and/or controlled. That is to say the parameter value that is involved in the target value or actual value and characterizes the fresh air flow or the exhaust gas recirculation flow. Appropriate parameter values for the corresponding controller control are contained in the control parameters.

The procedure according to the invention will be described below on the example of a diesel internal combustion engine. But the present invention is not limited to the application on the diesel internal combustion engine, it can also be applied on other internal combustion engines, especially on the gasoline internal combustion engine of direct injection type.

A certain gas quantity ML22 containing a certain oxygen component MO22 is supplied to the internal combustion engine 100 via a high-pressure fresh air line 102 . The parameter value MO22 is also called pre-combustion oxygen composition. The high pressure fresh air line 102 consists of two parts. The first part is indicated at 102a and the second part at 102b. The first section corresponds to the line up to the mixing of the exhaust gases. The second section 102b corresponds to the line after exhaust gas mixing. A regulating valve 104 is arranged in the first part 102a. The air in the first section of the high-pressure fresh air line 102a has a temperature T2 and a pressure P2. Fresh air MA flows through this part of the high-pressure fresh air line, or through a regulating valve.

Ambient air passes through low pressure fresh air line 108 to compressor 106 and then flows through regulator valve 104 into high pressure fresh air line 102 . The air volume ML21 with the oxygen component MO21 flows into the high-pressure fresh air line 102 via the compressor. The air quantity ML21 with the oxygen component MO21 flowing in via the low-pressure fresh air line 108 corresponds to the air quantity with the corresponding oxygen component flowing in via the compressor 106 or via the regulating valve 104 in the standstill state. There is a pressure P21 and a temperature T21 between the compressor 106 and the regulating valve.

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

An air volume ML31 with an oxygen component MO31 flows from the internal combustion engine 100 into the high-pressure exhaust gas line 110 . The parameter value MO31 is also referred to as post-combustion oxygen composition. There is a temperature T3 and a pressure P3 in the high-pressure exhaust gas line 110 . These values are also referred to as exhaust gas pressure P3 and exhaust gas temperature T3.

From high-pressure exhaust gas line 110 to turbine 112 , an air volume ML32 is also referred to as the air volume passing through the turbine. Exhaust gas passes from the turbine 112 to a low-pressure exhaust gas line 114 , which is also referred to as exhaust line 114 . In the low-pressure exhaust gas line there is a temperature P4 and a pressure P4.

Turbine 112 drives compressor 106 via shaft 111 . The rotational speed NL of the shaft is referred to as the supercharger rotational speed. The behavior of the turbomachine and thus of the entire supercharger can be influenced by means of the supercharger regulator 113 . For actuation, booster regulator 113 is acted upon with actuation signal LTV, which causes the booster to be displaced by stroke LH. The parameter value LH is also called the booster stroke and the parameter value LTV is called the booster duty ratio.

There is a connection between high-pressure exhaust gas line 110 and high-pressure fresh air line 102 , which is referred to as exhaust gas recirculation line 116 . Through this exhaust gas recirculation line 116 flows an air quantity MR comprising the oxygen component MOA. The cross section of the exhaust gas recirculation line 116 is preferably controllable by means of an exhaust gas recirculation valve 118 . For actuation, exhaust gas recirculation controller 119 is supplied with actuation signal ATV, which causes exhaust gas recirculation valve 118 to be displaced by stroke AH. The parameter value AH is also referred to as the EGR stroke and the parameter value ATV as the EGR duty ratio.

Preferably, the rotational speed N of the crankshaft and/or camshaft of the internal combustion engine is detected by means of rotational speed sensor 101 . Others are also provided with a quantity regulating device 103 which determines the injected fuel quantity ME supplied to the internal combustion engine. To this end, the adjusting mechanism 103 is acted upon with the quantity signal ME.

As shown in Fig. 2, the procedure according to the invention is described by means of a block diagram. An actual value determination unit 200 determines the actual value of the fresh air flow from various input parameters (not shown). In a simple variant, actual value determination unit 200 is a sensor which directly determines the fresh air flow. In a modified embodiment, a model calculation as described, for example, in DE19963358 is used for determining the actual value. The fresh air flow there corresponds to the parameter value ML21.

The output signal of the actual value determination unit 200 reaches the controller 220 via the logical operation unit 205 . Logic unit 225 acts on the output signal of controller 220 , which in turn acts on regulating valve 104 with a control variable value. The output signal of the setpoint value filter 210 is at the second input of the logical operation unit 205 with a negative sign, and the output signal of the setpoint value predetermining unit 215 is also supplied as an input to the setpoint value filter 210 . The rated value predetermining unit 215 predetermines the rated value of the expected fresh air flow MA according to different operating characteristic parameters and different working states. Furthermore, the output signal of target value filter 210 reaches hybrid position model 230 . In addition, the model 230 processes the output signals from various sensors 232 which determine the signal for the temperature T3 between the output of the internal combustion engine and the input of the turbine, the temperature between the output of the compressor and the control valve T21 and speed N signal. In addition to these sensors other sensory signals may be obtained and processed by the model 230 .

The switching model 235 of the control valve is loaded with the output signal of the model 230 . Model 230 supplies a signal to conversion model 235 with regard to the fresh air flow MA and the pressure P22 , which corresponds to the pressure upstream of the intake of the internal combustion engine. Furthermore, the signals of different sensors 240 characterizing the pressure P21 and the temperature T21 between the output of the compressor and the regulating valve 104 are supplied to the conversion model 235 . Instead of sensor 240 , it is also possible to provide a model for determining these parameter values on the basis of other parameter values. The output signal of the conversion model 235 reaches the logic unit 225 via a characteristic curve 245 . Model 230 , associated with switching model 235 and characteristic curve 245 , acts as a control variable pre-controller for control valve 104 .

A parallel branch line for the regulation of the exhaust gas recirculation flow MR is identified with a corresponding reference number. The output signal of logic unit 325 is supplied to exhaust gas recirculation valve 118 , and the output signal of controller 320 is awaited at the input of logic unit 325 . The output signal of the actual value determination unit 300 is supplied as an input parameter to a logical operation unit 305 , and the output signal of the logical operation unit 305 is in turn supplied to a controller 320 . The actual value determination unit 300 is formed similarly to the actual value determination unit 200 , that is, it can be formed by a sensor or a model. Setpoint value predetermination unit 315 predetermines a setpoint value for the exhaust gas recirculation flow, which likewise reaches logic unit 305 via setpoint value filter 310 , or to model 230 . Instead of the exhaust gas recirculation flow, the exhaust gas recirculation rate can also be predetermined as a target value. Model 230 loads second conversion model 335 with signals characterizing pressure P22 upstream of the intake of the internal combustion engine and exhaust gas recirculation flow MR. Furthermore, conversion model 335 processes the signals of sensor 340 , in particular pressure P3 and temperature T3 between the exhaust port of the internal combustion engine and the inlet of the turbine. Instead of sensor 340 , it is also possible to provide a model for determining these parameter values on the basis of other parameter values. The output signal of the second conversion model 335 reaches the logical operation unit 325 through the second characteristic curve 345 .

The regulator 220 regulates the fresh air flow MA from the target value predetermined unit 215 to a predetermined target value. For this purpose, the actual value prepared by actual value determination unit 200 is compared with the filtered target value. Based on the deviation of the setpoint value from the actual value, the control variable for acting on the control valve 104 of the regulator 220 is then predetermined. The actual value determination unit 200 can be formed by a sensor which directly determines the fresh air flow, or else by a model as disclosed, for example, in DE19963358.

This adjustment is superimposed on the precontrol. The pilot control essentially consists of a model which predetermines the control parameters of a control valve 104 starting from the setpoint value of the fresh air flow. The model includes at least two submodels. A submodel 230 replicates the mixing position, ie the area between the EGR valve, the regulating valve 104 and the intake of the internal combustion engine. Another submodel 235 includes a switching model of the control valve 104 . The output signal of this model, which corresponds to the desired effective control valve flow area, is converted into a control variable for control valve 104 by means of characteristic curve 245 .

This means that the pilot control starts from the fresh air flow MA and the setpoint values of the various operating characteristic parameters, in particular the temperature and pressure parameters, to calculate the desired effective flow area of the control valve and from this to calculate the pilot control value. Likewise, the controller calculates the control variable value of the control valve from the deviation between the setpoint value and the actual value of the fresh air flow. In particular, the two parameter values are added in the logic unit to form a superposition of the adjusted parameter values.

A corresponding control circuit with pilot control is likewise provided for the exhaust gas recirculation flow MR. Setpoint value predetermining unit 315 here predetermines a corresponding setpoint value, which is filtered in filter 310 and compared in logic unit 305 with the actual value of actual value determining unit 300 . As actual value determination unit 300 , sensors are likewise preferably used which directly measure the exhaust gas recirculation flow. Since such sensors are very expensive, expensive and cost-intensive, here too, in a preferred embodiment, a model corresponding to the model of the actual value determination unit is used, which determines these parameter values starting from other operating characteristic parameter values. From the deviation between the target value and the actual value, controller 320 calculates a control variable for controlling exhaust gas recirculation valve 118 .

In addition, a pilot control is provided, in which a pilot control value is likewise predetermined by means of a model based on a target value. The model includes a first submodel modeling the mixing position, and a transition model for the exhaust gas recirculation valve. A characteristic curve is attached to the model.

This means that, based on a comparison between a first setpoint value characterizing the fresh air flow characteristic and a first actual value, it is possible to predetermine the control parameter of the first regulator, preferably a control valve. Furthermore, based on a comparison between a second setpoint value characterizing the exhaust gas recirculation flow characteristic and a second actual value, a control parameter of the second controller, preferably the exhaust gas recirculation valve, can be predetermined.

That is to say, a parallel arrangement is provided, in which the desired value of each fresh air flow or the desired value of the exhaust gas recirculation flow can be set to a predetermined desired value. In a preferred variant, the control parameter determined by the control is superimposed on the pilot control value. It is particularly advantageous to use setpoint values which are simultaneously supplied to the control circuit for forming the pilot control value. A model is used for forming the pilot control value, which includes at least a mixed position modeling or a first or a second sub-model acting as a controller switching model, correspondingly in a preferred variant the actual value determination unit can also be formed by the model, It determines the actual value starting from different operating characteristic parameter values.

It is particularly advantageous if the exhaust gas recirculation flow, ie the flow through the exhaust gas recirculation valve, is predetermined as a setpoint value and the actual value is adjusted to the predetermined setpoint value. Alternatively, the exhaust gas recirculation rate can also be predetermined as a target value and adjusted to the target value.

It is advantageous for each of the fresh air flow and the exhaust gas recirculation flow to have a control circuit, wherein the control circuit includes on the one hand a regulator and on the other hand a pilot controller. That is to say that both parameter values are adjusted to the desired value independently of one another.

According to the present invention, the pilot control should be able to predetermine the time curves of the control parameters of the control valve and the exhaust gas recirculation valve, so that the system is able to follow changes in the desired value by means of this pilot control alone. In extreme cases, the regulators 220 and 320 can thus be completely dispensed with, or rather can be switched off in certain operating states. It is important that the model for converting the setpoint value into the control variable contributes to the effect of the pilot control. The model includes what is considered to be a mixing location of fresh air and exhaust gas recirculation with a volume V22 and pressure P22 container. There is also a submodel that replicates the exhaust gas recirculation valve and the regulating valve as throttle valves. Important input parameters for these models are the pressure P3 after the exhaust port of the internal combustion engine and before the turbine, before the control valve and after the compressor in the EGR rate or the setpoint value of the EGR flow rate and the setpoint value of the air flow The pressure P21 and the pressure P22 in the intake line, ie between the intake of the internal combustion engine and the exhaust gas recirculation valve or control valve, the temperature T3 downstream of the exhaust of the internal combustion engine.

The parameter values P3, P21, P22, T21 and T3 can be directly measured by sensors, or can be calculated from other operating characteristic parameter values with the help of models. The model described inter alia in DE19963358 is suitable as such a model. As setpoint values MR and MA for the exhaust gas recirculation rate and air flow used by the model, preferably the same setpoint values are used which are also supplied to the controller. Based on these input parameters, the model provides a time profile of the effective flow area of the control valve and/or the exhaust gas recirculation valve. It is reproduced by characteristic curve 245 or 345 or an expensive dynamic model as the control variable of the control valve and/or the exhaust gas recirculation valve.

The rated value predetermining unit 215 or 315 predetermines a corresponding rated value of an adjustment parameter according to different working parameters and working states. When operating parameters are changed or when changing to another operating state, there is usually a discontinuous process of setpoint value. In general, the corresponding parameter value cannot track a discontinuous or jumping process such as the rated value. This results in regulation deviations that the controller is trying to control. All add up to undesired regulator behavior. According to the invention, the setpoint value filter 210 or 310 therefore filters the setpoint value predetermining units so that the setpoint values are generated in a continuous process and these predetermined values can be tracked by the entire system at any time. That is to say, the setpoint value filter adapts the time course of the setpoint value to the time course of the entire system or the time course of the control variable. The target value filter 210 or 310 is therefore to generate a dynamically smooth target value process. In addition the filter should provide the time derivatives of these parameter values.

Model 230 calculates the desired fresh air flow and pressure P22 in the intake manifold from various input parameters. As input parameters, the model 230 uses temperature T3, temperature T21 before the regulator valve, dynamic smooth rated air flow, time derivative of dynamic smooth rated air flow, dynamic smooth EGR rate, dynamic smooth EGR rate time Derivative and engine speed. Based on these parameter values, model 230 calculates the setpoint air flow ML through regulating valve 104 , the setpoint exhaust gas recirculation flow through the exhaust gas recirculation valve and the setpoint pressure P22 in the mixing tank.

Conversion models 235 and 335 calculate the effective flow area of the respective throttle valve from the desired setpoint flow to flow through the throttle valve. For this, the pressure and/or temperature upstream of the throttle valve and the pressure and/or temperature downstream of the throttle valve are used. The input parameters of the regulator valve model 245 are the pressure P21 before the regulator valve and after the compressor, the pressure P22 in the intake pipe, and the temperature T21 before the regulator valve. The input parameters of the model 335 of the exhaust gas recirculation valve 118 are the pressure P3 after the exhaust port of the internal combustion engine and upstream of the turbine, the pressure P22 in the intake manifold, the temperature T3 after the exhaust port of the internal combustion engine and the temperature T3 through the exhaust gas recirculation valve 118 The flowing nominal exhaust gas recirculation flow rate MR.

The target values for the effective flow area of the control valve and the exhaust gas recirculation valve are converted via characteristic curves 245 and 345 into control parameter values for the control valve and the exhaust gas recirculation valve. In addition, instead of characteristic curves, more expensive dynamic models can also be used.

This advantage is obtained by means of pre-controlling, which can react very quickly to changes in the desired value. That is, a very fast steering characteristic is obtained. At the same time the system dynamics have been taken into account here. This means that not only the exhaust gas recirculation rate, or the exhaust gas recirculation flow rate, but also the air flow rate can be adapted very quickly to changing conditions by means of the pilot control. This is particularly advantageous when switching between different operating states, such as entering regenerative operation, or exiting regenerative operation. Because the two regulation circuits are independent of each other and there is no feedback at all in the system without the regulator, no stability problems will arise in this configuration. If an additional controller is used, it can only adjust the disturbance influence and the model accuracy, since the steering behavior is guaranteed by the precontrol. The combination of the two regulators is represented by the hybrid position model 230 , ie the regulators are separated, so that the use is significantly simplified.

It is particularly advantageous if, in certain operating states, only the pilot controller is active and the controller is dispensed with, ie the controller is switched off. For example, it can be implemented in such a way that the connection between controller 220 and logic unit 225 or between controller 320 and logic unit 325 is interrupted by means of a switching device when a certain operating state exists. Such an operating state is, for example, when a small control deviation causes a large change in the value of the control parameter. In such an operating state, there is a slight oversensitivity between the value of the controlling parameter and the value of the controlled parameter. In such an operating state, the controller is then dispensed with and only the pilot control value is used for controlling the controller. The regulator is thus protected and protected against disturbance influences. This is also very advantageous in terms of deviation.

The example of an air flow controller with the aid of a control valve in regenerative operation shows the following meaning: In the region of the larger opening of the control valve, the influence of the position of the control valve on the air flow is practically insignificant. If an attempt is made to adjust the target value in this less sensitive range by means of a controller, the controller can cause large deviations in the controlled variable value due to measurement noise, which can unnecessarily burden the control valve. When using the model-based pre-controller, the regulator is cut off in this less sensitive area. Pre-controllers provide a much smoother process of tuning parameters than regulators in less sensitive areas. The drive of the regulator is thus protected and disturbing influences on the air system are avoided.

Typically, a regulator with PI characteristics, in particular, is used as regulator 220 or 320 . Part I essentially forms the ratio between the setpoint value and the actual value with respect to the signed area. If a jump-like process is predetermined for the control parameter value, the limited passing interval dynamics and controller dynamics result in a time-delayed change of the regulated actual value. For this reason, the jumpy rating process leads to a non-physical, limited component of the I part. In order to remove this component again, the regulator has to oscillate up and down in the other direction relative to the desired value. This behavior leads to poor control behavior and can only be mitigated by corresponding control parameter values. However, at corresponding control parameter values, poor guiding properties can again occur.

According to the invention this effect can be significantly reduced by the target value filters 210 and 310 . This makes it possible to adapt the course of the setpoint value to the dynamics of the control interval and/or the dynamics of the controller by means of the filter 210 or 310 . It can thus be achieved that the target value is filtered such that it has the same or at least a similar time behavior as the controller and/or the entire control interval. For example, if the regulator has the PT1 characteristic, then a filter with the PT1 characteristic will be used. As a result, the area critical for the composition of the I part is significantly reduced. The regulator can now be set on a larger K1, since undesired components of the I part are avoided.

The arrangement according to the invention of the setpoint value filters 210 and 310 enables a dynamic adaptation of the setpoint value to the interval characteristic. The effective nominal flow area is calculated from this adapted nominal value procedure. This parameter value is used not only for calculating the pilot control value via model 230 and models 235 and 335 , but also as a desired parameter value for controller 210 or 320 . The calculation of the control deviation reproduces the non-modeled residual dynamics, for example the controller dynamics of this control variable via the dead time element and the PT1 element. As a result of this measure, the controller 220 or 320 only has to adjust the model accuracy and the disturbance influence and can be set at a corresponding speed.

If large control deviations occur in a controller with at least an integral characteristic, this can lead to relatively large values of the integral part at the control parameters necessary for good dynamic behavior. This large value causes oscillations up and down. This characteristic is undesirable. If a corresponding value of the control variable is selected without excessive oscillations or subharmonics, this can result in poor dynamics, ie the actual value will reach the corresponding target value very slowly.

In order to avoid this phenomenon, in a particularly advantageous embodiment, the value of the adjustment deviation, that is, the signal waiting to be processed in the logical operation unit 205 and/or in the logical operation unit 305, is limited to a maximum permissible value by means of a limiter. numerically.

Claims (9)

1. the method for controlling combustion engine, have the fresh air flow that first regulator is used to influence IC engine supply, have second regulator and be used to influence recirculated exhaust gas flow, wherein between first rating value of being used for the fresh air flow and first actual value relatively, can pre-determine first of first regulator and regulate parameter value, from between second rating value being used for exhaust gas flow and second actual value relatively, can pre-determine second of second regulator and regulate parameter value.

2. method according to claim 1 is characterized in that, first regulates the parameter value and the first pre-controlling value stack.

3. method according to claim 1 is characterized in that, second regulates the parameter value and the second pre-controlling value stack.

4. method according to claim 1 is characterized in that, first and/or second rating value is complementary with the time response of adjusting circuit.

5. method according to claim 1 is characterized in that, the first and/or second pre-controlling value can be pre-determined by at least the first and/or second rating value.

6. method according to claim 1 is characterized in that, the first and/or second pre-controlling value can pre-determine by means of first model.

7. method according to claim 1 is characterized in that, first and/or second actual value can pre-determine by means of second model.

8. method according to claim 1 is characterized in that, first model comprises that at least one is used for the submodel of hybrid position and/or regulator.

9. the device of controlling combustion engine, have the fresh air flow that first regulator is used to influence IC engine supply, have second regulator and be used to influence recirculated exhaust gas flow, has first mechanism, its by be used between first rating value of fresh air flow and first actual value relatively, pre-determine first of first regulator and regulate parameter value, pre-determine second of second regulator from the comparison between second rating value being used for exhaust gas flow and second actual value and regulate parameter value.