DE102008054954A1 - Method for operating internal combustion engine, involves preparing multiple different values of control variable, and preparing multiple values of another control variable - Google Patents

Abstract

The method involves preparing multiple different values of a control variable, and preparing multiple values of another control variable. The value of the former control variable is determined, where the former control variable or partial efficiency characteristic is corrected if the change of the initial value is detected. Independent claims are also included for the following: (1) a device for operating an internal combustion engine; and (2) a computer program with a program code.

Description

Technical area

The The invention relates to a method for operating an internal combustion engine with a drive quantity, in particular for operating an internal combustion engine at a desired Operating point for providing an output variable, in particular a method for providing a correction quantity for an internal combustion engine, a deviation between an actual operating condition and a predetermined by the Ansteuergröße Balance operating condition.

State of the art

combustion engines should be according to the desired Operating state operated with a certain air-fuel ratio become. For example, the optimal operation of a catalyst requires in a gasoline engine a complete Implementation of the injected fuel at a stoichiometric Balance, d. H. with an air-fuel ratio with a lambda value of 1. On the other hand, the optimal drive torque of the Internal combustion engine provided at a lambda value of about 0.85. In certain circumstances can also other lambda values to achieve certain desired or optimal operating conditions of the Be useful combustion engine.

at Internal combustion engines for operating a motor vehicle are often lambda sensors provided in the exhaust system to measure the lambda value and according to a Lambda control to adjust the air-fuel ratio and the injection quantity. For simpler, operated with an internal combustion engine surrounded devices such Lawnmower, Leaf Blower and the like, however, usually for cost reasons no Lambda sensor provided. Also, the lambda sensor in case of a defect or during cold running of the internal combustion engine in a motor vehicle not a reliable one Lambda value provide so that the internal combustion engine without a Lambda control must be operated Is no measured lambda value to disposal, so far z. B. in a gasoline engine, the amount of fuel according to a predicted momentary air filling in the cylinders and a desired one Lambda value calculated and supplied to the internal combustion engine. D. H. the internal combustion engine should be supplied with so much fuel, that mathematically the desired Air-fuel ratio (lambda value) sets. The desired Lambda value is, for example, due to smoothness depending on the engine temperature, or for reasons optimal conversion of the catalyst or optimization of the Motor power or for the thermal protection of components specified, wherein the efficiency set by varying the lambda value is lambda efficiency is called. However, component tolerances, Aging effects, design-related parameter dispersion of individual Components and similar Effects the injected amount of fuel from the calculated amount of fuel can vary, so that the actual lambda value of the desired Lambda value is different.

In other cases is also the combustion position, d. H. the crankshaft angle to Time of maximum implementation of the chemical energy of the fuel (Focus of combustion), often not known exactly. As a rule, gasoline and diesel engines have no cost reasons Cylinder pressure sensors on, so that the focus of combustion is not can be measured directly. When controlling the Otto internal combustion engine becomes common a combustion efficiency (efficiency by variation of Combustion center) below 100%, for example, a Torque reserve available or general Stellmomenteneingriffe to realize in positive as well as negative direction. At petrol engines depends on that Combustion position substantially from the ignition angle and the instantaneous Operating point and is relatively accurately adjustable while at Diesel engines only indirectly adjust the combustion position by adjusting of injection time and duration or a profile of the injection can be influenced by fuel. Also when setting the Combustion center or the ignition angle occurs at a Specification of the combustion efficiency or the Zündwinkelwirkungsgrades Deviations due to component tolerances, aging effects, changes of fuel properties and the like.

Generally There is the difficulty of operating conditions of an internal combustion engine adjust if there is no direct feedback on reaching the desired Operating state is available. In these cases become control variables for the internal combustion engine arithmetically or according to a reference model determined. In a control of the internal combustion engine with the corresponding drive size should the desired one Set operating status. However, there are usually deviations between the desired Operating condition and the actual Operating condition due to component tolerances, aging effects, a changing one Fuel composition and the like.

It is an object of the present invention to provide a method and a device for providing a correction variable, with the aid of which the specification of an operating state of the internal combustion engine via a first control variable can be improved and in particular deviations of the performance of an expected performance z. B. due to component tolerances, aging effects or a changing fuel composition can be compensated.

Disclosure of the invention

These The object is achieved by the method for providing a correction quantity according to claim 1 and by the device according to the independent claim solved.

Further advantageous embodiments are specified in the dependent claims.

• – Bereitstellen von mehreren verschiedenen Werten der ersten Ansteuergröße, wobei der ersten Ansteuergröße eine erste Teilwirkungsgradkennlinie zugeordnet ist, die eine Abhängigkeit eines Wirkungsgrades des Verbrennungsmotors bezüglich der ersten Ansteuergröße beschreibt, wobei den mehreren verschiedenen Werten der ersten Ansteuergröße durch die erste Teilwirkungsgradkennlinie definierte erste Teilwirkungsgrade zugeordnet sind;
• – Bereitstellen von mehreren Werten mindestens einer zweiten Ansteuergröße, die den mehreren Werten der ersten Ansteuergröße jeweils zugeordnet sind, wobei der zweiten Ansteuergröße eine zweite Teilwirkungsgradkennlinie zugeordnet ist, die eine Abhängigkeit des Wirkungsgrades des Verbrennungsmotors bezüglich der zweiten Ansteuergröße beschreibt, wobei die erste Teilwirkungsgradkennlinie von der zweiten Ansteuergröße und die zweite Teilwirkungsgradkennlinie von der ersten Ansteuergröße unabhängig sind, wobei die Werte der zweiten Ansteuergröße den jeweiligen Werten der ersten Ansteuergröße zugeordnet werden, indem für jeden Wert der ersten Ansteuergröße die folgenden Schritte durchgeführt werden:
• – Ermitteln des dem Wert der ersten Ansteuergröße zugeordneten ersten Teilwirkungsgrades,
• – Ermitteln eines zweiten Teilwirkungsgrades zu dem ersten Teilwirkungsgrad, so dass das Produkt aus dem ersten Teilwirkungsgrad und dem zweiten Teilwirkungsgrad für jeden bereitgestellten Wert der ersten Ansteuergröße konstant ist, und
• – Auslesen eines dem zweiten Teilwirkungsgrad zugeordneten Werts der zweiten Ansteuergröße aus der zweiten Teilwirkungsgradkennlinie;
• – Zeitlich aufeinanderfolgendes Ansteuern des Verbrennungsmotors mit den mehreren verschiedenen Werten der ersten Ansteuergröße und den entsprechend zugeordneten Werten der zweiten Ansteuergröße;
• – Detektieren, ob sich als Folge des zeitlich aufeinanderfolgenden Ansteuerns des Verbrennungsmotors mit den mehreren verschiedenen Werten der ersten Ansteuergröße und den entsprechenden Werten der zweiten Ansteuergröße eine Änderung der Ausgangsgröße ergibt;
• – Korrigieren der ersten Ansteuergröße oder der ersten Teilwirkungsgradkennlinie, wenn eine Änderung der Ausgangsgröße detektiert wird.

According to a first aspect, there is provided a method of operating an internal combustion engine, wherein the internal combustion engine is controlled with a plurality of drive quantities to provide an output of the internal combustion engine; with the following steps:

• - Providing a plurality of different values of the first control variable, wherein the first control variable is associated with a first partial efficiency curve, which describes a dependence of an efficiency of the internal combustion engine with respect to the first control variable, wherein the plurality of different values of the first control variable by the first partial efficiency characteristic defined first partial efficiencies are assigned ;
• Providing a plurality of values of at least one second control variable associated with the plurality of values of the first drive variable, wherein the second drive variable is associated with a second partial efficiency characteristic that describes a dependence of the efficiency of the internal combustion engine on the second drive variable, wherein the first partial efficiency characteristic of the the second drive quantity and the second partial efficiency curve are independent of the first drive quantity, wherein the values of the second drive quantity are assigned to the respective values of the first drive quantity by performing the following steps for each value of the first drive quantity:
• Determining the first partial efficiency assigned to the value of the first control variable,
• Determining a second partial efficiency to the first partial efficiency such that the product of the first partial efficiency and the second partial efficiency is constant for each provided value of the first control variable, and
• - Reading a value assigned to the second partial efficiency of the second control variable from the second partial efficiency curve;
• - Timing of the internal combustion engine with the several different values of the first control variable and the correspondingly assigned values of the second control variable;
• Detecting whether there is a change in the output quantity as a result of the chronologically sequential activation of the internal combustion engine with the several different values of the first control variable and the corresponding values of the second control variable;
• - Correcting the first drive quantity or the first partial efficiency curve when a change of the output variable is detected.

A The idea of the method described above is basically to make a correction of a first control variable, with a Response of an internal combustion engine to a specification of the first Control variable modified is, so that the predetermined by the first control variable operating state is taken in the internal combustion engine. Because the presence of the given operating condition but not in all cases directly through Measuring or deriving is verifiable, is changed in the above method by changing operating points in the internal combustion engine and a resulting performance of the internal combustion engine carried out a correction of the first drive quantity.

The Adjusting the current value of the first control variable can especially so performed be that at least two control variables each between at least be varied two operating points, wherein the variation of the control variables is chosen so that the output output from the engine does not change when no correction of the first control variable is necessary, i. H. it occurs no deviation between the actual output and the desired by the first control variable Output size. Dodges the output of the internal combustion engine from the expected output, may be a change a running behavior, in particular a change in the engine speed, be determined with their help or depending on the correcting the first drive variable is performed. On this way, the operating state caused by the first control variable influenced, so that the running behavior of the internal combustion engine adapted can be, so that it the desired running behavior equivalent.

Furthermore, the respectively defined by the first and the second partial efficiency curve dependence of the first and second partial efficiency of the respective control variable to the off be proportional.

Especially can correct the first control variable by applying the first control variable with a Value of a correction variable can be performed wherein, in particular, the value of the correction variable is selected as a function of the change in the output variable.

alternative or additionally can be corrected by the first partial efficiency a shifting of the first partial efficiency characteristic over the first control variable are performed, wherein especially the extent of the Moving from the change the output variable is selected depending.

According to one embodiment can the change the output size a change a speed of the internal combustion engine and / or by a change a manipulated variable of a active speed control, in particular an idle speed control, be determined.

According to one another embodiment the first control variable of a Default size for an air-fuel ratio and the second control variable a Default size for one firing angle for the Engine correspond, wherein the first partial efficiency curve corresponds to a lambda efficiency curve, wherein the correcting by a reduction of the specification of the air-fuel ratio a certain absolute or relative amount or by a Shifting the lambda efficiency curve in the direction of higher air-fuel ratios is performed by a certain absolute or relative amount, if a difference of a value of the output variable when driven with a higher value the default value of the air-fuel ratio minus one Value of the output variable during activation with a lower value of the default air-fuel ratio is negative and the gradient of the lambda efficiency curve is negative or when the difference is positive and the gradient of the lambda efficiency curve is positive, and where correcting by increasing the Default value for the air-fuel ratio to a certain absolute or relative amount or by a Shifting the lambda efficiency curve in the direction of lower air-fuel ratios is performed by a certain absolute or relative amount when the difference is negative and the gradient of the lambda efficiency curve is positive or if the difference is positive and the gradient the lambda efficiency curve is negative.

According to one alternative embodiment may the first control variable one Default value for a firing angle and the second drive quantity one Default value for an injection quantity, wherein the first partial efficiency characteristic an ignition angle efficiency curve where correction is by changing a default value the ignition angle is performed by a certain absolute or relative amount, so the ignition timing after late is shifted, or by shifting the Zündwinkelwirkungsgradkennlinie in the direction of earlier ignition is performed by a certain absolute or relative amount, if a difference of a value of the output variable when driven with a higher Value of the first tax quantity minus one Value of the output variable during activation with a lower value of the first drive quantity is negative and the gradient the ignition angle efficiency curve is negative or if the difference is positive and the gradient the ignition angle efficiency curve is positive, and being corrected by a change a default value of the ignition angle is performed by a certain absolute or relative amount, so the ignition timing early is shifted, or by shifting the Zündwinkelwirkungsgradkennlinie in the direction of later Ignition times around a certain absolute or relative amount is performed, if the difference is negative and the gradient of the ignition angle efficiency curve is positive or if the difference is positive and the gradient the ignition angle efficiency curve negative is

Farther can the plurality of temporally successive values of the first drive quantity Applying a predetermined control variable with a temporal excitation function be generated.

According to one another embodiment, the several values of the first control variable are determined by a by a default value of the first drive with the help the first partial efficiency curve specific value of the first partial efficiency modified with an excitation function, in particular multiplied, is a time course of several first partial efficiencies and subsequently with the aid of the first partial efficiency curve from the first several Partial efficiencies determined the multiple values of the first control variable become.

• – eine erste Einrichtung zum Bereitstellen von mehreren verschiedenen Werten der ersten Ansteuergröße, wobei der ersten Ansteuergröße eine erste Teilwirkungsgradkennlinie zugeordnet ist, die eine Abhängigkeit eines Wirkungsgrades des Verbrennungsmotors bezüglich der ersten Ansteuergröße beschreibt, wobei den mehreren verschiedenen Werten der ersten Ansteuergröße durch die erste Teilwirkungsgradkennlinie definierte erste Teilwirkungsgrade zugeordnet sind;
• – eine zweite Einrichtung zum Bereitstellen von mehreren Werten mindestens einer zweiten Ansteuergröße, die den mehreren Werten der ersten Ansteuergröße jeweils zugeordnet sind, wobei der zweiten Ansteuergröße eine zweite Teilwirkungsgradkennlinie zugeordnet ist, die eine Abhängigkeit des Wirkungsgrades des Verbrennungsmotors bezüglich der zweiten Ansteuergröße beschreibt, wobei die erste Teilwirkungsgradkennlinie von der zweiten Ansteuergröße und die zweite Teilwirkungsgradkennlinie von der ersten Ansteuergröße unabhängig sind, wobei die zweite Einrichtung ausgebildet ist, um die Werte der zweiten Ansteuergröße den jeweiligen Werten der ersten Ansteuergröße zuzuordnen, indem für jeden Wert der ersten Ansteuergröße die folgenden Schritte durchgeführt werden:
• – Ermitteln des dem jeweiligen Wert der ersten Ansteuergröße zugeordneten ersten Teilwirkungsgrades,
• – Ermitteln eines zweiten Teilwirkungsgrades zu dem ersten Teilwirkungsgrad, so dass das Produkt aus dem ersten Teilwirkungsgrad und dem zweiten Teilwirkungsgrad für jeden bereitgestellten Wert der ersten Ansteuergröße konstant ist, und
• – Auslesen eines dem zweiten Teilwirkungsgrad zugeordneten Werts der zweiten Ansteuergröße aus der zweiten Teilwirkungsgradkennlinie;
• – eine Einrichtung zum zeitlich aufeinanderfolgenden Ansteuern des Verbrennungsmotors mit den mehreren verschiedenen Werten der ersten Ansteuergröße und den entsprechend zugeordneten Werten der zweiten Ansteuergröße;
• – eine Einrichtung zum Detektieren, ob sich als Folge des zeitlich aufeinanderfolgenden Ansteuerns des Verbrennungsmotors mit den mehreren verschiedenen Werten der ersten Ansteuergröße und den entsprechenden Werten der zweiten Ansteuergröße eine Änderung der Ausgangsgröße ergibt;
• – eine Einrichtung zum Korrigieren der ersten Ansteuergröße oder der ersten Teilwirkungsgradkennlinie, wenn eine Änderung der Ausgangsgröße detektiert wird.

In another aspect, an apparatus for operating an internal combustion engine, wherein the internal combustion engine is driven with a plurality of drive variables to provide an output of the internal combustion engine; with the following steps:

• A first device for providing a plurality of different values of the first An control variable, wherein the first control variable is associated with a first partial efficiency curve, which describes a dependence of an efficiency of the internal combustion engine with respect to the first control variable, wherein the plurality of different values of the first control variable by the first partial efficiency characteristic defined first partial efficiencies are assigned;
• A second device for providing a plurality of values of at least one second control variable, which are assigned to the plurality of values of the first control variable, wherein the second control variable is associated with a second partial efficiency curve, which describes a dependence of the efficiency of the internal combustion engine with respect to the second control variable; the first partial efficiency characteristic of the second control variable and the second partial efficiency characteristic are independent of the first control variable, wherein the second means is arranged to assign the values of the second control variable to the respective values of the first control variable by performing the following steps for each value of the first control variable :
• Determining the first partial efficiency assigned to the respective value of the first control variable,
• Determining a second partial efficiency to the first partial efficiency such that the product of the first partial efficiency and the second partial efficiency is constant for each provided value of the first control variable, and
• - Reading a value assigned to the second partial efficiency of the second control variable from the second partial efficiency curve;
• A device for sequentially activating the internal combustion engine with the several different values of the first control variable and the correspondingly assigned values of the second control variable;
• - means for detecting whether there is a change in the output as a result of the sequential driving of the internal combustion engine with the plurality of different values of the first drive quantity and the corresponding values of the second drive quantity;
• A means for correcting the first drive quantity or the first partial efficiency characteristic when a change in the output quantity is detected.

According to one another aspect is provided by a computer program that, if it is performed on a data processing unit, the above method performs.

Brief description of the drawings:

embodiments The invention will be explained in more detail with reference to the accompanying drawings. It demonstrate:

1 a schematic representation of an engine system with an internal combustion engine;

2 a functional representation of an engine system for performing a method for determining a lambda correction amount;

3 a flowchart for illustrating the method steps of the method for determining the lambda correction amount;

4 a Zündwinkelwirkungsgradkennlinie an Otto engine;

5 a lambda efficiency curve of an Otto engine;

6a to 6c Diagrams for illustrating the characteristics of the lambda efficiency and the ignition angle efficiency as well as their product in a matched internal combustion engine and in internal combustion engines, in which the actual lambda value deviates from a desired lambda value;

7 a functional representation of another engine system for performing a method for determining a Zündwinkelkorrekturgröße; and

8th a flowchart for illustrating the method that in the engine system of 7 is performed.

Description of embodiments

1 shows an engine system 1 with an internal combustion engine 2 , The internal combustion engine 2 is via an air supply section 3 Air is supplied and exhaust gas via a Abgasabführungsabschnitt 4 dissipated. In the air supply section 3 is a throttle 5 provided by an engine control unit 10 is controllable. The position or position of the throttle 5 affects the over the air supply section 3 the internal combustion engine 2 supplied air mass flow or the amount of air supplied. In the air supply section 3 is upstream of the throttle 5 an air mass sensor 6 an indication of the currently in the air supply section 3 provides flowing air mass flow.

In the present example, the internal combustion engine corresponds 2 an Otto engine in which for ever the cylinder an injection valve 7 is provided to inject a certain amount of fuel into a combustion chamber of the corresponding cylinder before an upcoming combustion. Alternatively, the injection may also be in the air supply section 3 in a downstream of the throttle 5 be injected suction pipe. The ignition of the provided in the combustion chamber of the corresponding cylinder air-fuel mixture is effected by a spark plug 8th ,

It is an engine control unit 10 provided to engine sized sensors mounted in the engine system, such as, for. For example, the information about the air mass flow from the air mass sensor 6 , one with the help of a speed sensor 9 detected actual engine speed n one of the internal combustion engine 2 driven crankshaft, one with the help of a temperature sensor 11 recorded information about a current engine temperature T. The engine control unit 10 controls the position of the throttle depending on engine sizes or quantities derived therefrom 5 , the amount of fuel flowing through the injector 7 is injected, in particular over the injection period, and the focal point of combustion over the ignition timing of the ignition of the air-fuel mixture through the spark plug 8th ,

The combustion of the air-fuel mixture in the combustion chamber of the cylinder of the internal combustion engine 2 formed exhaust gas is in a Abgasabführungsabschnitt 4 pushed out. In the exhaust discharge section 4 can be a lambda sensor 13 be arranged, which measures the oxygen content in the exhaust gas and from a current lambda value λ _akt the engine control unit 10 supplies. In this example it is assumed that the engine control unit 10 no lambda value is provided, either because the lambda sensor 13 can not determine a reliable indication of the lambda value of the air-fuel mixture due to a not yet reached operating temperature or because the gasoline engine shown has no or a defective lambda sensor.

The engine control unit 10 sets a torque request MA in a control of the internal combustion engine 2 for providing a driver input corresponding to a drive torque MA by the position of the throttle 5 is varied to the air supply and thus the air filling in the internal combustion engine 2 adjust. The current air charge rlp in the cylinders is determined or in the engine control unit 10 predicted with the help of other engine sizes and over a predetermined lambda value, ie a desired lambda value, the corresponding amount of fuel to be injected is determined and an ignition by the spark plug 8th performed at a certain firing angle to achieve a certain drive torque.

In the Otto engine, it is generally the case that the torque Mihd generated in the high-pressure phase, on which the drive torque depends, is calculated as follows: Mihd = mioptl1 (rl, n) · ETALAM (λ act ) · ETADZW (DZW) where λ _{akt is} the actual actual lambda value, mioptl1 the operating point-dependent, maximum drive torque which is generated at the best possible ignition in the high pressure loop and a lambda value of 1 and primarily from the fresh air filling rl in the cylinders and the engine speed n of the internal combustion engine 2 ETALAM corresponds to the lambda efficiency, which indicates the dependency of the provided drive torque on the actual lambda value, and ETADZW the ignition angle efficiency (combustion position efficiency). The Zündwinkelwirkungsgrad indicates about the choice of the ignition angle ZW adjustable efficiency of the engine 2 and depends in particular on the location of the actual combustion center. As a rule, the highest drive torque is obtained at a combustion center of gravity at a crankshaft angle of approximately 8 ° CA after top dead center of the piston movement in the cylinder. At earlier or later combustion focus (ignition angle deviation DZW <> 0) takes the drive torque relative to the maximum drive torque at the present operating point or the efficiency of the internal combustion engine 2 from.

A course of the ignition angle efficiency as a partial efficiency characteristic is in 4 shown. The ignition angle efficiency ETADZW reaches its maximum with no deviation of the ignition angle ZW from the optimal ignition angle, an ignition angle deviation DZW of 0, and drops with increasing amounts of Zündwinkelabweichung DZW.

The course of the lambda efficiency ETALAM as partial efficiency characteristic is in 5 shown. The characteristic of the lambda efficiency is normalized to the stoichiometric balance of λ = 1, so that the efficiency is assumed to be 100%. A maximum of the lambda efficiency ETALAM is obtained at about 0.85, with lambda values greater or smaller than 0.85, the lambda efficiency ETALAM decreases. From the above formula you can see that from the engine 2 provided drive torque can be determined both by adjusting the lambda efficiency ETALAM and by setting the Zündwinkelwirkungsgrades ETADZW (assuming constant air or stationary operation of the internal combustion engine).

In the present internal combustion engine 2 it is a gasoline engine whose actual lambda value λ _akt , ie its actual air-fuel ratio, can not be readily determined by measuring or deriving other quantities. The amount of fuel supplied depends on a predefined air charge rlp in the cylinders of the internal combustion engine 2 and is determined by determining the injection period ti (determined by the period of opening of the respective injection valve 7 ). Due to tolerances of components, such as the injection valve 7 Changing component properties due to aging effects, changing the composition of fuel so that fuel properties change, such. As the viscosity, or other factors, the actual lambda value λ _{akt of} the air-fuel mixture in the combustion chambers of the cylinder of the desired lambda value λ _Soll , according to that in the engine control unit 10 the amount of fuel to be injected is determined differ. This leads to a changed compared to the desired operating state operating condition and thus usually deteriorated operating conditions of the internal combustion engine 2 ,

It is now proposed that at a certain operating point (preferably in steady state operation), the various drive variables that the efficiency of the internal combustion engine 2 can be varied so that the resulting drive torque would remain unchanged despite variation of the control variables, if an actual size or output variable of the internal combustion engine characterizing the operating point 2 correspond to the desired operating point. In the illustrated embodiment, this means that the resulting drive torque would remain unchanged despite variation of the desired lambda value λ _Soll or a dependent fuel factor and the corresponding ignition angle, if the real lambda value λ _akt , with the internal combustion engine 2 is operated, the desired lambda value λ _Soll would correspond. Thus, for example, the specification of the desired lambda value λ _{Soll can be} varied so that varied lambda values λ (t1), λ (t2) are used to determine the injection quantity rk. At the same time, according to the drive torque of the internal combustion engine to be provided 2 required ignition angle ZW (according to the above formula) varies so that the drive torque remains the same.

An indication of the resulting drive torque can be determined by observing the running behavior of the internal combustion engine, for. For example, by observing the engine speed n. If the actual lambda value λ _akt deviates from the desired lambda value λ _setpoint , then the variation of the control variables in the opposite direction with respect to the resulting efficiencies causes a change in the engine speed n, which can be correspondingly evaluated. For example, with the aid of the evaluation of the observed running behavior, a corresponding lambda correction variable can be adapted or determined.

In 2 is a preferred embodiment for implementing this method as a block diagram and in 3 shown as a flow chart.

In 2 are the engine system 2 and the engine control unit 10 shown in detail. The engine control unit 10 includes an injection calculation path in which in an air system model block 21 a predicted air filling rlp determined and multiplied by a mixture factor fak_gemisch an injection quantity rk using a multiplication block 22 is determined. The injection quantity rk is in an injection time unit 23 converted into an injection duration ti, which is sent to the internal combustion engine 2 is appropriately communicated to fuel with the injectors 7 to those by the injection time unit 23 At certain times for a predetermined period of time to inject fuel into the active cylinder to be operated.

Furthermore, a firing angle calculation block 24 is provided, which determines, depending on a desired Zündwinkelwirkungsgrad ETADZW an ignition angle ZW, to which the air-fuel mixture is ignited in the active cylinder.

In a filling setpoint calculation block 25 is a z. B. converted by a driver request specific specification for a drive torque in a filling setpoint, resulting in a position of the throttle 5 results. The adjustment of the throttle 5 is indicated by the signal rl _set at the throttle 5 performed.

In the present engine system 1 is the indication of the running behavior of the internal combustion engine 2 derived from a reaction of an idle speed controller to a speed deviation from a target speed n _target . The method is thus carried out only with active idle speed control, whereby a steady-state operating condition is ensured. Alternatively, the method can also be performed by a mere observation of the speed changes as a result of the variation of the desired lambda value λ _setpoint and of the ignition angle.

An idle speed controller 26 receives from the internal combustion engine 2 , in particular of the speed sensor 9 , The engine speed n and determines it as a manipulated variable adjusting torque M _Stell , on the one hand the Zündwinkelberechnungsblock 24 is fed and on the other an adaptation block 27 is supplied to adapt an injection amount correction quantity frk-adap and thereby set a mixture value fak_gemisch corresponding to a predetermined lambda value.

The lambda efficiency ETALAM and the ignition angle efficiency ETADZW are determined via the selection of a desired lambda value λ _setpoint and the selection of an ignition angle deviation DZW, and the efficiency of the internal combustion engine can be determined 2 be set according to the required actuating torque M _Stell .

The idle speed controller 26 includes a differential element 261 for determining an indication of the speed deviation, ie, for example, a difference of the current engine speed n from a predetermined set speed n _target of the speed curve, and outputs the speed deviation Δn to an integration block 262 and to a proportional block 263 out. The control torque M _Stell results from the addition of the integration block 262 determined integrator portion and that of the proportional block 263 determined proportional share. The integrator portion becomes the fill setpoint calculation block 25 provided so that depending on the integrator share a position of the throttle valve 5 is determined.

The course of the method according to the invention is in 3 shown as a flow chart. The procedure is in the engine control unit 10 executed and can be implemented programmatically as software.

wobei sich der Zündwinkel ZW per Definition der Kennlinie des Zündwinkelwirkungsgrades aus einem optimalen Zündwinkel ZWopt zuzüglich der Zündwinkelabweichung DZW ergibt. Ist die Leerlaufdrehzahlregelung aktiv, so wird der Adaptionsblock 27 aktiviert und es wird der vorgegebene Lambdasollwert λ_Soll (Ansteuergröße) mit einem ersten Anregungsfaktor gemäß einer zeitlichen Anregungsfunktion f_anreg(t1) multipliziert, um einen ersten variierten Lambdawert λ(t1) im Schritt S2 bereitzustellen, oder in sonstiger Weise beaufschlagt. Der erste variierte Lambdawert λ(t1) entspricht einem Vorgabewert für den tatsächlichen Lambdawert und dient als eine Angabe für die einzuspritzende Kraftstoffmenge. Alternativ kann der gewünschte Lambdawert λ_Soll auch in einen Einspritzmengenfaktor, z. B. durch Kehrwertbildung, umgerechnet werden, der dann mit der Anregungsfunktion f_anreg(t) beaufschlagt wird. Die Anregungsfunktion f_anreg(t) liefert allgemein einen zeitlich variierenden Multiplikationsfaktor zur Beaufschlagung des bzw. zur Multiplikation mit dem gewünschten Lambdawert λ_Soll. Der resultierende erste Anregungsfaktor f_anreg(t1) zu einem Zeitpunkt t1 wird mit dem gewünschten Lambdawert λ_Soll multipliziert, vorzugsweise in einem Multiplikationsblock 271, und man erhält den ersten variierten Lambdawert λ(t1). Das Ergebnis wird einem Zündwinkelwirkungsgradkompensationsblock 272 zugeführt.In the step S1, it is determined whether the idle speed control is active. If the idle speed control is active (alternative: yes), the actuating torque M _{Stell is} determined from the instantaneous engine speed n according to the known idle speed control as a control variable and the control torque M _Stell the Zündwinkelberechnungsblock 24 supplied, so that there the ignition angle ZW is selected according to the required actuating torque M _Stell . The selection is carried out according to the formula given above for determining the torque Mihd, wherein an ignition angle deviation DZW for a given lambda value λ _Soll and the resulting lambda efficiency ETALAM and the maximum, resulting in the present by the engine speed n and the air filling rlp determined operating point Drive torque results from:

wherein the ignition angle ZW per definition of the characteristic of the Zündwinkelwirkungsgrades from an optimal ignition angle ZWopt plus the Zündwinkelabweichung DZW results. If the idle speed control is active, then the adaptation block 27 is activated and it is the predetermined lambda _desired value λ _target (control variable) multiplied by a first excitation factor according to a temporal excitation function f_anreg (t1) to provide a first varied lambda λ (t1) in step S2, or applied in any other way. The first varied lambda value λ (t1) corresponds to a default value for the actual lambda value and serves as an indication of the amount of fuel to be injected. Alternatively, the desired lambda value λ _{setpoint can} also be converted into an injection quantity factor, eg. B. by inverse, be converted, which is then acted upon by the excitation function f_anreg (t). The excitation function f_anreg (t) generally provides a temporally varying multiplication factor for the application of or for multiplication with the desired lambda value λ _setpoint . The resulting first excitation factor f_anreg (t1) at a time t1 is multiplied by the desired lambda value λ _Soll , preferably in a multiplication block 271 and the first varied lambda value λ (t1) is obtained. The result becomes a firing efficiency compensation block 272 fed.

The firing efficiency compensation block 272 determines in step S3 from the variation of the lambda value λ _Soll (the first varied lambda value λ (t1)) resulting first varied Zündwinkelwirkungsgradkompensationsfaktor feta_zw_komp (t1) for compensating the efficiency of the ignition angle ZW and provides this the Zündwinkelberechnungsblock 24 to disposal. The firing efficiency compensation block 272 determines the first Zündwinkelwirkungsgradkompensationsfaktor feta_zw_komp (t1) so that the product of the resulting from the first varied lambda λ (t1) lambda efficiency ETALAM and from the with the aid of the first Zündwinkelwir kungsgradkompensationsfaktor feta_zw_komp (t1) determined Zündwinkelwirkungsgrad ETADZW over all realistic ( ie implementable) lambda values gives constant value. D. h., The lambda _setpoint λ _target by the excitation function z. B. increased by a certain value, this results in an operating point-dependent lambda efficiency change. The lambda efficiency change results in a change in the ignition angle efficiency to be set, so that the product of the resulting lambda efficiency and the changed ignition angle efficiency remains constant. The ignition angle efficiency compensation factor feta_zw_komp thus indicates the degree of the change in the ignition angle efficiency ETADZW to be set.

In the ignition angle calculation block 24 is using the in the map of the 4 stored function for the ignition angle efficiency ETAD ZW an ignition angle deviation DZW based on the determined by the current ignition angle ZW operating on the Zündwinkelwirkungskennlinie the 4 and the ignition angle efficiency ETADZW changed by the first firing angle efficiency compensation factor feta_zw_komp (t1). The instantaneous ignition angle therefore results from the optimum ignition angle ZWopt, which results from the control torque M _Stell , and an ignition angle displacement DZW, which results from the change in the ignition angle efficiency. It applies ZW = ZWopt (M parking ) + DZW With DZW = ETADZW -1 (1 / ETALAM (λ Should ))

It there is a change Ignition angle ZW (t1) based on the first varied lambda value λ (t1).

The first varied lambda value λ (t1) becomes a correction block 273 supplied, in which the first varied lambda value λ (t1) is converted into a first injection quantity factor, z. B. by inverse, and with the injection quantity correction variable frk-adap that of the adaptation unit 274 is multiplied. The resulting product is mixed as mixture factor fak_gemisch the multiplication block 22 so that a first injection amount rk (t1) corresponding to the first varied lambda value λ (t1) applied to the injection amount correction amount may be calculated (step S5).

The actuating torque M _Stell resulting from the application of the first varied injection quantity rk (t1) becomes the adaptation unit 274 supplied and initially stored in a step S6.

In steps S7, S8, S9, S10, analogous method steps with a second varied lambda value λ (t2) deviating from the first varied lambda value λ (t1) are performed for steps S2, S3, S4 and S5. The second varied lambda value λ (t2) is obtained by multiplying the desired lambda value λ _Soll by a resulting second excitation factor f_anreg (t2) at a time t2. The second varied lambda value λ (t2) also depends on the desired lambda value λ _Soll and deviates therefrom, preferably with an opposite sign. By applying the second varied ignition angle ZW (t2) and by injecting the second injection quantity rk (t2) of fuel, a corresponding actuating torque M _Stell results.

By the ignition angle efficiency compensation in the ignition angle efficiency compensation block 272 is achieved that the variation of the lambda values λ (t1), λ (t2) is carried out torque neutral, since the change in the lambda efficiency is compensated by the change of the Zündwinkelwirkungsgrades ETADZW when the predetermined desired lambda value λ _Soll in the internal combustion engine 2 is ideally adjustable. Due to tolerances, aging effects and changes in fuel composition, deviations of the fuel path (blocks 21 . 22 . 23 ) of injected fuel, which can lead to a deviation of the actual lambda value λ _akt from the desired lambda value λ _Soll .

The deviation of the actual lambda value λ _akt results in a shift of the operating point on the lambda efficiency curve ETALAM (λ), so that the set drive torque is different from that of the idle speed controller 26 desired setting torque M _Stell deviates. This results in a variation of the lambda value, a change in the engine speed n, which is an engagement of the idle speed controller 26 leads. It results in a behavior that in 6 is represented by three characteristic diagrams.

In the in 6 The three efficiency curves shown are the individual efficiency components ETALAM, ETADZW and the efficiency product from the lambda efficiency resulting from the actual lambda value λ _akt and the ignition angle efficiency resulting from the compensation of the variation of the lambda efficiency.

In 6a the case is shown in which the predetermined desired lambda value λ _Soll , ideally from the internal combustion engine 2 is set to an air-fuel ratio of λ _akt = λ _{target is} set.

In 6b the case is shown in which the actual lambda value λ _{akt of} the air-fuel mixture with respect to the lambda _setpoint λ _Soll is too lean by 10%, so that the engine control unit 10 in the case of the incorrect assumption of the lambda value λ adjusts an ignition angle efficiency ETADZW, which leads to a profile of the efficiency product between the lambda efficiency ETALAM and the ignition angle efficiency ETADZW, which tends to decrease with increasing lambda values λ, so that with an increase in the lambda value λ (reduction of the injection quantity) and a corresponding increase in the combustion engine 2 output firing efficiency ETADZW nevertheless a reduction of the engine speed n or an increase of the manipulated variable torque of the idle speed controller 26 is detectable.

In 6c the case is shown in which the actual lambda value λ _{akt is} smaller than the desired lambda value λ _soll , ie, the air-fuel ratio is richer than specified by the lambda setpoint λ _soll . In this case, when the actual lambda value λ _{akt is} misunderstood, an ignition angle efficiency ETADZW results, which leads to an increasing characteristic curve of the efficiency product of the lambda efficiency and the ignition angle efficiency, which is shown in FIG 6c is shown. This leads to a rising profile of the efficiency product over the lambda value λ _soll , so that when the lambda value is increased (reduction of the injection quantity) and a corresponding increase in the ignition angle efficiency ETADZW an increase in the engine speed and thus a decrease in the actuating torque occurs.

In step S11, in the adaptation unit, the resulting setting torques are compared with one another when the first varied lambda value λ (t1) and the first varied ignition angle ZW (t1) and the second varied lambda value λ (t2) and the second varied ignition angle ZW (t2) are applied a deviation z. B. calculated in the form of a difference of the control moments. In other words, the adaptation unit 274 detects the control moments at the applied varied lambda values λ (t1), λ (t2) and thus determines the gradient of the efficiency product by the lambda _setpoint λ _setpoint .

In step S12, an adaptation of the injection quantity correction variable frk-adap is now carried out as a function of the setting torque difference. The injection amount correction variable frk-adap is adapted so that it is possible to detect via a difference of the actuating torques on the basis of the applied varied lambda values λ (t1), λ (t2), whether the actual lambda value λ _akt in the internal combustion engine 2 from the desired lambda value λ _set to lean (in the direction of higher lambda values) or to bold (in the direction of lower lambda values).

If, for example, a lower drive torque, ie a speed reduction, is detected when injecting a fuel quantity reduced by a higher varied lambda value, this will be reflected in the idle speed controller 26 in an increase of the setting torque M _Stell to set the engine speed n to a target speed n _target . Is that in the adaptation unit 274 determined gradient of the adjusting torque M _Stell with respect to the varied lambda values λ (t1), λ (t2) positive, the injection quantity correction variable must be increased frk-adap. If the gradient is negative, the injection quantity correction variable frk-adap must be reduced. The resulting setting moment M _Stell effects in the adaptation unit 274 an adaptive adjustment of the injection quantity until the resulting control torque M _{Stell is} no longer dependent on the variation of the injection quantity.

The adaptation preferably takes place iteratively. Alternatively or additionally, the adaptation can also be carried out, for example, depending on the height of the gradient of the various actuating moments M _Stell .

To the adaptation of the injection quantity correction value frk-adap becomes too Step S1 jumped back, so that the variation by jumping between the first and the second varied lambda value λ (t1), λ (t2) continuously carried out as long as the idle speed control is active.

In particular, to account for aging effects of the engine system, the method may be performed when the engine system is idling and the idle speed governor 26 is active. Alternatively, the method can also without active idle speed controller 26 be performed, instead of the actuating torque M _Stell then speed changes directly in the adaptation unit 274 must be evaluated. In order to exclude other influences on the engine speed n, however, a stationary operating state must be ensured.

Another engine system is in the block diagram of 7 shown. In essence, the block diagram is similar to the 7 the block diagram of 2 , Instead of the uncertain lambda value only assumed that the Zündwinkelwirkungsgrad can not be sufficiently accurately determined or can not be implemented with sufficient accuracy in a specific ignition angle. The method is in the flow chart of 8th shown.

The following is only on the differences to the engine system of 2 received, wherein like reference numerals represent blocks of the same or similar function.

The fuel path going through the blocks 21 . 22 . 23 is formed, is another multiplication block 29 extended, so that the fuel quantity rk to be injected by a lambda factor fr from a known lambda control 30 is determined. The lambda control 30 sets the lambda factor for depending on a deviation between a z. B. with the help of the lambda sensor 13 measured actual lambda value λ _is and a desired lambda value λ _Soll , which is provided by a motor function for the realization of a lambda efficiency controlled drive torque available. It is assumed that in this way the actual lambda value λ _{ist is set} to the desired lambda value λ _setpoint .

Furthermore, the multiplication block takes into account 22 now no longer the mixture factor but an injection quantity compensation factor frk-komp, which should compensate for variations in the Zündwinkelwirkungsgrades ETADZW.

In step S21, it is checked whether the idle speed control is active. If this is the case (alternative: yes), then in step S22 a first varied firing angle efficiency ETADZW (t1) is determined by multiplying a predetermined target value of the firing angle efficiency ETADZW_Soll with a first firing function value from an excitation function f_anreg. This is in place of the adaptation block 27 in the engine system of 7 an adaptation block 28 intended. The adaptation block 28 contains a multiplication block 281 , that of a corresponding engine control function in the engine control unit 10 the desired value of the ignition angle efficiency ETADZW_Soll is specified.

Analogous to the method described above, the first varied firing angle efficiency ETADZW (t1) becomes a lambda efficiency compensation block 282 fed. The lambda efficiency compensation block 282 Furthermore, a _desired lambda value λ _{Soll is} supplied, so that a first injection amount compensation factor frk-komp (t1) (step S23) is calculated, which determines a first varied injection quantity rk (t1) by multiplication with a predicted air charge rlp. The first varied injection quantity rk (t1) results as follows: ETALAM (λ) = 1 / (ETADZW), With ETADZW = ETADZW_Soll · f_anreg (t), wherein the injection quantity compensation factor frk-komp is given by: frk-komp = ETALAM -1 (1 / (· ETADZW_Soll f_anreg (t)) and rk = frk-komp · fr · rlp

The first varied firing angle efficiency ETADZW (t1) becomes the firing angle calculation block 24 and a first varied ignition angle ZW (t1) is calculated by determining the first varied ignition angle ZW (t1) at the operating point of the ignition angle efficiency curve determined by the control torque M _{Stell of} the idle speed control (step S25). In other words, the varied ignition angle efficiency ZW (t1) becomes the excitation factor ETADZW_anreg of the ignition angle calculation block 24 provided so that the over the Zündwinkelberechnungsblock 24 provided ignition angle ZW is varied accordingly. The variation of the ignition angle results from the inverted ignition angle efficiency curve ETADZW, so that a change in the ignition angle efficiency results in a changing ignition angle deviation DZW. The first varied ignition angle ZW (t1) becomes the internal combustion engine 2 provided.

The actuating torque M _Stell resulting from the application of the first varied ignition angle ZW (t1) and the first varied injection quantity rk (t1) becomes in the adaptation unit 284 detected and initially stored in a step S26.

In steps S27, S28, S29, S30, method steps analogous to steps S22, S23, S24 and S25 are performed with a second varied firing angle efficiency ETADZW (t2) deviating from the first varied firing angle efficiency ETADZW (t1). The second varied firing angle efficiency ETADZW (t2) likewise depends on the desired firing angle efficiency ETADZW_Soll and deviates therefrom preferably with an opposite sign. By applying the second varied injection quantity correction factor frk-komp (t2) and injecting the second varied injection quantity rk (t2) of fuel, a corresponding engine torque results as a reaction and then a corresponding actuating torque M _Stell via the idling control.

Also in this embodiment causes the variation of the Zündwinkelwirkungsgrades or the resulting variation of the ignition angle due to the counter-compensation in the form of a variation of the injection quantity no change in the drive torque of the internal combustion engine 2 if the Zündwinkelwirkungsgrad over the specification of the ignition angle is exactly adjustable.

In particular, in the case of inaccuracies of the efficiency which can be set via the ignition angle on account of aging phenomena or component tolerances or due to changes in the fuel composition, a firing angle correction value dzwopt-adapdem Zündwinkelberechnungsblock can be 24 provide that is achieved by the variations of the ignition angle ZW and the amount of fuel rk no torque change of the actuating torque M _Stell occurs.

For this purpose, as in the embodiment of 2 an adaptation unit 284 is provided, which increases or decreases the Zündwinkelkorrekturwert dzwopt adapabhängig caused by the variation of the Zündwinkelwirkungsgrades change of the actuating torque M _Stell . The firing angle correction value dzwopt-adap is typically in the firing angle calculation block 24 additively to the ignition angle ZW, to the internal combustion engine 2 is spent pitched. For example, dzwopt-adap can be understood as an offset adaptation to the optimum ignition angle. For this purpose, in step S31, the setting torque M _{Stell is} detected with respect to the second varied Zündwinkelwirkungsgrades ETADZW (t2) and determines a corresponding gradient of the control torques with respect to the Zündwinkelwirkungsgrades. The ignition angle provided is increased by the ignition angle correction value dzwopt-adap (earlier ignition) when the gradient of the actuating torque is negative, and vice versa.

The adaptation takes place in step S32 in the adaptation unit 284 , whereby, depending on the sign of the gradient of the setting torque, the ignition angle correction value dzwopt-adap can be iteratively adjusted.

The Adaptation is carried out as previously described and can be performed according to a Adaptation factor, with which the gradient value is taken into account, in their speed be adjusted.

The excitation function f_anreg of the embodiments described above is essentially freely selectable. However, it should be ensured that despite possible deviation of the current lambda value λ _akt from the _desired lambda value λ _Soll no lambda values in the internal combustion engine 2 may occur in which combustion in the cylinders is no longer guaranteed. This also applies analogously to the variation of the ignition angle efficiency ETADZW, ignition angles outside of determinable ignition angle limits should not be permitted. In general, an excitation function f_anreg makes sense, which varies the _desired lambda value λ _Soll or the ignition angle efficiency ETADZW in a range of -5 to + 5% up to a range of -10% to + 10%.

Ideally, it would be sufficient to specify fixed varied values for the lambda value or the ignition angle efficiency. However, this would lead to sudden changes in the control of the internal combustion engine 2 to lead. However, these can not be implemented in particular by the fuel path, z. B. due to wall film effects, so that can result in sudden changes in the injection quantity effects that from the engine 2 influence delivered torque so that the adaptation process is not properly carried out. For this reason, it is provided to select the excitation function f_anreg such that the transitions between the varied lambda values or ignition angle efficiencies with limited gradients are provided so as not to change the corresponding values abruptly but with a predetermined time profile. Furthermore, the excitation function should take levels that are maintained for a certain recovery time, so that dynamic effects can subside.

According to one Variant of the embodiment described above may be considered second Control quantity in addition to Injection quantity also proportional to the amount of fresh air adjusted so be to set a fixed air-fuel ratio, eg. For example, one for the conversion the catalyst optimum air-fuel ratio of λ = 1, maintain. With the Variation of only the injection quantity can be the chemical energy be varied with the same amount of oxygen while at additional Variation of the filling the chemical energy can be varied while maintaining the air-fuel ratio can.

Instead of An iterative adaptation method can also be used for other optimization methods such as gradient descent methods and the like, by the corresponding correction values for the lambda value or the ignition angle to teach in an improved way.

The described method leaves also transferred to diesel engines, wherein instead of the Zündwinkelwirkungsgrads combustion efficiency varies in an adjustable manner becomes. The adjustment of the combustion layer efficiency is done via the Injection duration, the injection time or an injection profile of fuel.

Claims (13)

Method for operating an internal combustion engine ( 2 ), wherein the internal combustion engine ( 2 ) is driven with a plurality of control variables (λ, rk, ZW) in order to determine an output variable of the internal combustion engine ( 2 ) to provide; comprising the following steps: - providing a plurality of different values of the first drive variable (λ (t1), λ (t2); ETADZW (t1), ETADZW (t2)), wherein the first drive variable is assigned a first partial efficiency characteristic (ETALAM, ETADZW), the one dependence of an efficiency of the internal combustion engine ( 2 ) with respect to the first drive quantity (λ (t1), λ (t2); ETADZW (t1), ETADZW (t2)), wherein the plurality of different values of the first drive quantity (λ (t1), λ (t2), ETADZW (t1 ), ETADZW (t2)) are assigned first partial efficiencies (ETALAM (t1), ETALAM (t2)) defined by the first partial efficiency curve (ETALAM, ETADZW); Providing a plurality of values of at least a second drive quantity (ZW (t1), ZW (t2), frk-komp (t1), frk-komp (t2)) corresponding to the several different values of the first drive quantity (λ (t1), λ (t2); ETADZW (t1), ETADZW (t2)) are respectively assigned, wherein the second drive variable (ZW (t1), ZW (t2); frk-komp (t1), frk-komp (t2)) a second partial efficiency characteristic (ETADZW, ETALAM) is assigned, which is a function of the efficiency of the internal combustion engine ( 2 ) with respect to the second drive quantity (ZW (t1), ZW (t2), frk-komp (t1), frk-komp (t2)), the first partial efficiency characteristic (ETALAM, ETADZW) being determined by the second drive variable (ZW (t1) , ZW (t2), frk-komp (t1), frk-komp (t2)) and the second partial efficiency characteristic (ETADZW, ETALAM) from the first drive quantity (λ (t1), λ (t2); ETADZW (t1), ETADZW (t2)) are independent, wherein the values of the second drive quantity are assigned to the respective values of the first drive quantity (λ (t1), λ (t2), ETADZW (t1), ETADZW (t2)) for each value of the first drive quantity (λ (t1), λ (t2); ETADZW (t1), ETADZW (t2)) the following steps are carried out: determining the respective value of the first drive variable (λ (t1), λ (t2); ETADZW (t1 ), ETADZW (t2)), determining a second partial efficiency to the first partial efficiency, such that the product of the first partial efficiency and the second partial efficiency is provided for each ready partial efficiency value of the first drive variable (λ (t1), λ (t2); ETADZW (t1), ETADZW (t2)) is constant, and - reading out a value of the second drive variable (ZW (t1), ZW (t2), frk-komp (t1), frk-comp (t2)) assigned to the second partial efficiency from the second partial efficiency curve (ETALAM, ETADZW); - Time sequential activation of the internal combustion engine ( 2 ) with the several different values of the first drive variable (λ (t1), λ (t2), ETADZW (t1), ETADZW (t2)) and the correspondingly assigned values of the second drive variable (ZW (t1), ZW (t2); -comp (t1), frk-comp (t2)); Detecting whether, as a consequence of the sequential activation of the internal combustion engine ( 2 ) with the several different values of the first drive variable (λ (t1), λ (t2), ETADZW (t1), ETADZW (t2)) and the correspondingly assigned values of the second drive variable (ZW (t1), ZW (t2); -comp (t1), frk-komp (t2)) gives a change in the output; - correcting (S12; S13) the first drive quantity (λ (t1), λ (t2); ETADZW (t1), ETADZW (t2)) or the first partial efficiency characteristic when a change of the output quantity is detected. The method of claim 1, wherein the first and the second partial efficiency curve in each case defined dependence of the first or second partial efficiency of the respective drive quantity to the Output proportional is. Method according to one of claims 1 and 2, wherein the correcting (S12; S13) of the first drive quantity Applying the first control variable is performed with a value of a correction variable, in particular the value of the correction variable is selected as a function of the change in the output variable. Method according to one of claims 1 and 2, wherein the correcting (S12; S13) of the first partial efficiency characteristic by shifting the first partial efficiency characteristic curve is carried out over the first control variable, The method of claim 4, wherein the amount of displacement from the change the output variable is selected depending. Method according to one of claims 1 to 5, wherein the change of the output variable by a change of a rotational speed (n) of the internal combustion engine ( 2 ), by a change in a drive torque of the internal combustion engine ( 2 ) and / or by a change in a manipulated variable (M _Stell ) an active speed control, in particular an idle speed control, is determined. Method according to one of claims 1 to 6, wherein said first drive quantity (λ (t1), λ (t2)) of an air-fuel ratio default value and said second drive quantity (ZW (t1), ZW (t2)) of a default quantity for a firing angle (ZW) for the internal combustion engine ( 2 ), wherein the first partial efficiency curve corresponds to a lambda efficiency curve (ETALAM), wherein the correction is achieved by a reduction of the specification variable for the air / fuel ratio by a specific absolute or relative amount or by shifting the lambda efficiency curve in the direction of higher air / fuel ratio Ratios is performed by a certain absolute or relative amount, when a difference of a value of the output when driven with a higher value of the target value of the air-fuel ratio minus a value of the output when driven with a lower value of the default value for the air-fuel Ratio is negative, and the gradient of the lambda efficiency characteristic is negative or when the difference is positive and the gradient of the lambda efficiency characteristic is positive, and wherein the correction is achieved by increasing the default value for the air-fuel ratio is performed by a certain absolute or relative amount or by shifting the lambda efficiency curve in the direction of lower air-fuel ratios by a certain absolute or relative amount, if the difference is negative and the gradient is positive or if the difference is positive and the gradient of the lambda efficiency curve is negative. Method according to one of claims 1 to 6, wherein the first drive quantity corresponds to a default value for an ignition angle (ZW) and the second drive variable corresponds to a default value for an injection quantity (rk), the first partial efficiency characteristic corresponding to an ignition angle efficiency curve (ETADZW), wherein the correction is achieved by a change of a preset value of the ignition angle (ZW) is performed by a certain absolute or relative amount, so that the ignition timing is retarded, or is performed by shifting the Zündwinkelwirkungsgradkennlinie in the direction of earlier ignition timing by a certain absolute or relative amount, if a difference of a value of the output when driven with is a negative value of the first drive quantity minus a value of the output variable when actuated with a lower value of the first drive variable and the gradient of the ignition angle efficiency curve is negative or if the difference posi tiv and the gradient of the ignition angle efficiency characteristic is positive, and the correction is performed by changing a default value of the ignition angle (ZW) by a certain absolute or relative amount so that the ignition timing is advanced, or by shifting the ignition angle efficiency characteristic in the direction of later ignition timing by a certain absolute or relative amount when the difference is negative and the gradient of the ignition angle efficiency characteristic is positive or when the difference is positive and the gradient of the ignition angle efficiency characteristic is negative. Method according to one of claims 1 to 8, wherein the plurality different values of the first control variable by applying a Default values for the first drive variable (λ (t1), λ (t2); ETADZW (t1), ETADZW (t2)) with a temporal excitation function (frk-anreg (t)) be generated. Method according to one of claims 1 to 9, wherein the plurality different values of the first control variable (λ (t1), λ (t2); ETADZW (t1), ETADZW (t2)) be determined by a by a default value for the first Control variable (λ (t1), λ (t2); ETADZW (t1), ETADZW (t2)) with the aid of the first partial efficiency curve Value of the first partial efficiency (ETALAM, ETADZW) with an excitation function (f_anreg (t)) is modified, in particular multiplied, by one temporal course of several first modified partial efficiencies and subsequently with the aid of the first partial efficiency curve from the first several modified partial efficiencies the several different values the first drive variable (λ (t1), λ (t2); ETADZW (t1), ETADZW (t2)). Method according to one of claims 1 to 10, wherein the method in a stationary operation of the internal combustion engine ( 2 ) is carried out. Device for operating an internal combustion engine ( 2 ), wherein the internal combustion engine ( 2 ) is driven with a plurality of control variables (λ, rk, ZW) in order to determine an output variable of the internal combustion engine ( 2 ) to provide; comprising: a first device for providing a plurality of different values of the first drive variable (λ (t1), λ (t2); ETADZW (t1), ETADZW (t2)), the first drive variable having a first partial efficiency characteristic (ETALAM, ETADZW ), which has a dependence of an efficiency of the internal combustion engine ( 2 ) with respect to the first drive quantity (λ (t1), λ (t2); ETADZW (t1), ETADZW (t2)), wherein the plurality of different values of the first drive quantity (λ (t1), λ (t2), ETADZW (t1 ), ETADZW (t2)) are assigned first partial efficiencies (ETALAM (t1), ETALAM (t2)) defined by the first partial efficiency curve (ETALAM, ETADZW); Second means for providing a plurality of values of at least a second drive quantity (ZW (t1), ZW (t2), frk-komp (t1), frk-komp (t2)) corresponding to the plurality of different values of the first drive quantity (λ ( t1), λ (t2), ETADZW (t1), ETADZW (t2)), respectively, the second drive quantity (ZW (t1), ZW (t2), frk-comp (t1), frk-comp (t2) ) a second partial efficiency characteristic (ETADZW, ETALAM) is assigned, which has a dependence of the efficiency of the internal combustion engine ( 2 ) with respect to the second drive quantity (ZW (t1), ZW (t2), frk-komp (t1), frk-komp (t2)), the first partial efficiency characteristic (ETALAM, ETADZW) being determined by the second drive variable (ZW (t1) , ZW (t2), frk-komp (t1), frk-komp (t2)) and the second partial efficiency characteristic (ETADZW, ETALAM) from the first drive quantity (λ (t1), λ (t2); ETADZW (t1), ETADZW (t2)) are independent, wherein the second means is adapted to calculate the values of the second drive quantity (ZW (t1), ZW (t2), frk-comp (t1), frk-comp (t2)) the respective values of the first Drive variable (λ (t1), λ (t2); ETADZW (t1), ETADZW (t2)) by assigning for each value of the first drive quantity (λ (t1), λ (t2); ETADZW (t1), ETADZW (t2 )), the following steps are performed: determining the first partial efficiency assigned to the respective value of the first drive variable (λ (t1), λ (t2); ETADZW (t1), ETADZW (t2)), determining a second partial efficiency with respect to the first Partial efficiency, so that the product out the first partial efficiency and the second partial efficiency for each provided value of the first drive quantity (λ (t1), λ (t2); ETADZW (t1), ETADZW (t2)) is constant, and - readout of the second partial efficiency ordered value of the second drive quantity (ZW (t1), ZW (t2), frk-komp (t1), frk-komp (t2)) from the second partial efficiency characteristic (ETALAM, ETADZW); A device for sequential activation of the internal combustion engine ( 2 ) with the several different values of the first drive quantity (k (t1), λ (t2), ETADZW (t1), ETADZW (t2)) and the correspondingly assigned values of the second drive variable (ZW (t1), ZW (t2); -comp (t1), frk-comp (t2)); A device for detecting whether, as a consequence of the temporally successive activation of the internal combustion engine ( 2 ) with the several different values of the first drive quantity (λ (t1), λ (t2), ETADZW (t1), ETADZW (t2)) and the corresponding values of the second drive quantity (ZW (t1), ZW (t2); -comp (t1), frk-komp (t2)) gives a change in the output; - means for correcting (S12; S13) the first drive quantity (λ (t1), λ (t2); ETADZW (t1), ETADZW (t2)) or the first partial efficiency characteristic when a change in the output quantity is detected. Computer program that when it is on a computing device accomplished is carried out, the method according to one of claims 1 to 10.