DE102012017204A1 - Method for operating optimized control fuel supply in combustion chamber of direct-injection spark-ignition engine of motor vehicle, involves utilizing engine controller, data memory and fuel quality detection unit arranged in motor vehicle - Google Patents

Abstract

The method involves utilizing an engine controller (1), a data memory (2) and a fuel quality detection unit (3), which are arranged in a motor vehicle. The fuel quality detection unit detects a currently used fuel quality (4) in a form of fuel data for a mixture formation (6). The fuel data (5) passes through and used by the engine controller. The engine controller computes the mixture formation by using a physical model (7). Independent claims are include for the following: (1) an engine controller with a data memory; and (2) a computer program product with a program code medium.

Description

The invention relates to a method, a motor control and a computer program product for the operation-optimized control of a fuel supply in a combustion chamber of a direct-injection spark-ignition internal combustion engine.

With the invention it is possible to ensure a good power delivery with low fuel consumption and at the same time to meet the increasingly stringent regulations and laws on pollutant emissions. For this purpose, the combustion processes in the cylinder are optimized. For this purpose, it is determined which fuel is burned in the cylinder.

For example, in the DE 10 2009 031 159 B3 a method for determining a fuel quality with a fuel sensor and use of a fuel pump is described. The method analyzes fuel quality by determining an electrical parameter of the fuel. This electrical parameter is measured by means of a fuel sensor comprising an electric motor with stator and rotor. An electrical parameter of the fuel is determined between the rotor and the stator, which is a measure of the fuel quality. The electric motor runs in this technical teaching in the wet, so in that fuel whose quality or quality is to be measured. On the basis of the electrical parameter, the alcohol content of the fuel can be determined. The determination of the electrical parameter for inferring the fuel quality can also take place in time before the internal combustion engine is put into operation. Furthermore, electrical parameters of the fuel can be processed in a control device and provided to a control unit of a vehicle in order to adapt the ignition timing and fuel supply to the engine of the vehicle to the current composition of the fuel. The focus of the described method is the determination of the fuel quality.

From the DE 103 46 314 A1 also results in a fuel quality sensor with motor control. In the system described, various aspects of engine operation are to be controlled with different fuel quality in terms of improved combustion and improved vehicle behavior. The fuel quality sensor uses acoustic waves to measure the viscosity and density of gasoline fuels. This predicts the quality of combustion during the starting process. Also, engine operating parameters such as fuel injection quantity, ignition timing, and fuel injection timing should be adjusted based on the sensor data. The engine control here is based on several parameters that are determined during engine operation. With these measures, the fuel quality is learned in a learning routine in the form of an iteration, which is part of the engine control, and the engine is regulated for optimized operation.

Object of the present invention is to provide for improved performance of a direct injection gasoline engine with changing fuel composition.

The object of this invention is achieved with a method having features of claim 1, with a motor controller having the features of claim 4 and with a computer program product having the features of claim 8. Advantageous developments of the invention are specified in the dependent claims.

Further advantageous features and embodiments will become apparent from the following description as well as from the figures. One or more of these features of one or more embodiments may be linked to additional refinements. The wording of the present claims is only a suggestion of a formulation of the subject invention. Thus, one or more features of the independent claims may be linked or substituted with one or more features of the specification.

The invention relates to a method for operating-optimized control of a fuel feed into a combustion chamber of a direct injection internal combustion engine of a motor vehicle, which uses an engine controller, a data memory and a fuel quality detection means, which are respectively arranged in the motor vehicle, and the fuel quality detection means a currently used fuel quality in the form of fuel data for a Mixture formation, this data passes and these are used by the engine control, the engine control calculates the mixture formation using a physical model, a mixture ignition capability of the calculated mixture formation judges and based on the judgment to be controlled operating parameters so that the mixture ignition capability in one of the operator the motor vehicle desired operating point is ensured.

With this method, it is possible to burn fuel qualities of ethanol, methanol and gasoline in almost any proportions. Depending on which fuel quality is burned in the combustion chamber, operating parameters for mixture formation, such as injection time, injection end, injection quantity, ignition point, Air requirement, valve control times controlled optimally.

Preferably, the physical model is the function. The function provides the possibility of assessing a mixture formation on the basis of the physical-based modeling of the mixture formation depicted in the function, wherein in particular the physical fuel properties are taken into account. This can happen through calculations as well as through calls to table values. The function requires, for example, that first the fuel properties are detected, which can be done for example by means of a suitable sensor, as described above, for example, in the prior art. By means of the detected composition of the fuel, the crucial properties such as the stoichiometric air requirement and the enthalpy of vaporization of the fuel can be determined via table values stored in the engine control.

An advantage of the method is, for example, that one does not need to perform a calibration of the above-mentioned parameters for the starting process and the warm-up according to an embodiment for each fuel. This is often still necessary, for example, in today's engine control systems for ethanol flex-fuel operation. In certain grades, a calibration of the parameters must be carried out for various mixing ratios of ethanol and gasoline. The engine control then interpolates between the calibrated interpolation points. If this engine control additionally operation with another third fuel, for. As butanol, allow the entire engine control would have to be calibrated for the possible mixing ratios of butanol. The proposed invention using, for example, a proposed function may maintain the existing engine control unit rating because the appropriate operating strategies and parameters will be selected as a result of the mixture formation modeling.

In a calibration example, the engine control unit according to an embodiment only with certain fuels - which preferably cover a wide range of different fuel properties - checked so that the parameters selected for the associated physical properties have a boot and warm-up result, as desired.

For this purpose, a function can take into account the mixture formation resulting from the physical fuel properties and above this, a mode of operation or parameters can be selected.

For example, the physical model may include a simplified computation or even simulation of flow processes in the cylinder and thus in the combustion chamber, whereby by means of, for example, the unsteady conservation equations for the gas phase and the liquid phase coupled are simply solved. Also can be used for this purpose adapted to the specific combustion chamber and the vehicle formula that z. B. covers the physical conditions through experimental results. In this case, for example, the grid is set so that the injection jet, its geometry as well as its droplet formation or atomization, for example, also included. Thus, for example, only for the injection nozzle, a separate model can be used, which takes into account the conditions such as occurring cavitation in an inlet of a nozzle hole and the emergence of a vapor state of the fuel. For example, a physical model is dedicated to beam formation in the combustion chamber. For example, at the beginning of the injection, the physical model may provide a characterization of a gas state by the gas temperature, the pressure in the combustion chamber, the flow field and the degree of turbulence. Preferably, a resulting gas density is used, which is determined from the pressure and the temperature. The beam propagation may preferably take place in the model from the point of view of the penetration depth of the beam and its beam angle. For example, it may be considered in the physical model that with increasing gas temperature an evaporation rate increases, whereas a drop concentration decreases. The model also takes into account, for example, that with increasing swirl the fuel is laterally deflected further. On the other hand, a middle region of the fuel jet, which is substantially still unvaporized, hardly or only slightly deflected, unless a geometry in the combustion chamber provides for this deflection.

In addition to a subdivision of the physical model into submodels for, for example, individual components such as injector, spray or the like, all this can be summarized in a single physical model. The model is preferably conceived such that the result can be assessed immediately via a calculation, as will be explained in more detail below.

Another approach to building the physical model is that mixture formation in the direct-injection spark-ignition internal combustion engine is based on the injection system forming a substantial part of it. Therefore, the physical model can in particular engine operating parameters such as an injection quantity, a mean injection rate, a nozzle opening pressure, and a nozzle hole diameter with include. Thus, for example, a mixture formation by a state of a cylinder charge, in particular taking into account the flow in the combustion chamber, as well as parameters such as supercharging pressure and compression ratio can be considered. Furthermore, the physical model may include wall influences. Also physical properties of the fuel used can be included.

• – wird die Kraftstoffmenge im Zyklus erhöht, kann beispielsweise die Einspritzdauer sich verlängern. Auch besteht die Möglichkeit, dass eine Erhöhung des Einspritzdruckes mit der Erhöhung der einzuspritzenden Kraftstoffmenge einhergeht.
• – wird auf eine mittlere Einspritzrate im Rahmen des physikalischen Modells abgestellt, so kann das physikalische Modell beispielsweise vorsehen, dass eine erhöhte mittlere Einspritzrate eine verkürzte Einspritzdauer bei erhöhtem maximalem Einspritzdruck vorsieht.
• – Das physikalische Modell kann zum Beispiel des Weiteren einen unterschiedlichen Druck bei der Einspritzung vorsehen. Dieser Druck kann beispielsweise über das Einspritzsystem direkt an der Düse vorliegen und damit ebenfalls die Einspritzung selbst beeinflussen. Beispielsweise kann dieses auch durch eine Änderung der geöffneten Düsenquerschnitte im Modell ebenfalls Berücksichtigung finden. Beispielsweise kann das physikalische Modell in Abhängigkeit von der Einspritzrate beziehungsweise der Einspritzmenge einen spezifischen Düsenquerschnitt vorsehen, wobei diesem Querschnitt angepasst ein spezieller Eintrittsstrahl zugeordnet ist. Des Weiteren kann beispielsweise im physikalischen Modell vorgesehen sein, dass die Düsenlochdurchmesser und die Anordnung der Düsendurchmesser insbesondere unter Berücksichtigung des Hubs des Einspritzventiles Berücksichtigung findet. Dadurch die Strahlausbreitung und letztendlich auch die Gemischbildung hiervon ebenfalls mit beeinflusst wird ist für die Frage der Gemischaufbereitung wie auch der schnellen Kraftstoffverdampfung derartiges beispielsweise mit im Modell abgebildet.

Preferably, the physical model is set up in such a way that an injection duration independent of the engine speed or a load-dependent control of an injection quantity via a change in the injection rate can be taken into account. For example, the physical model can take different influences into account:

• - If the amount of fuel in the cycle is increased, for example, the injection duration can be extended. There is also the possibility that an increase in the injection pressure is associated with the increase in the amount of fuel to be injected.
• - Is set to a medium injection rate within the physical model, the physical model may provide, for example, that an increased average injection rate provides a shortened injection duration at elevated maximum injection pressure.
• For example, the physical model may further provide a different pressure in the injection. This pressure can be present for example via the injection system directly to the nozzle and thus also influence the injection itself. For example, this can also be taken into account by changing the open nozzle cross sections in the model also. For example, the physical model can provide a specific nozzle cross-section as a function of the injection rate or the injection quantity, wherein a specific inlet jet is assigned to this cross section. Furthermore, it can be provided, for example, in the physical model that the nozzle hole diameter and the arrangement of the nozzle diameter are taken into account, in particular taking into account the stroke of the injection valve. As a result of this, the beam propagation and, ultimately, the mixture formation thereof are also influenced, for the question of mixture preparation as well as the rapid evaporation of the fuel, for example, in the model.

Furthermore, it has proven to be advantageous if the physical model also takes into account, as are the geometric dimensions of the combustion chamber and in particular also of the piston crown. The geometry of the piston as well as the angle of injection of the geometrical beam axis can influence the beam propagation and thus the mixture preparation. Depending on the time at which the injection takes place at which pressure, the respective position of the piston is therefrom, so that the distance of the piston bottom geometry from the injection injector's orifice differs. This can be taken into account by using the time in the model.

Further, the model may consider, for example, how the atomization of the fuel occurs depending on various parameters. According to one embodiment, it is provided, for example, that a jet break-up in the injection is described on the one hand by the use of the Reynolds number and on the other hand by the use of the no-nil number. The Reynolds number includes the nozzle diameter, an exit velocity, and a stock value of the liquid. The unconscious number describes the ratio of the toughness force to the surface forces and is also calculable accordingly. Considered, for example, in the model that with increasing Reynolds number shear stress forces on the surface gain in influence, so that with appropriate sizes different mechanisms for the atomization depending on the detected Reynolds number or Ohnesorge number can be used. For example, a work by Lefebre entitled "Atomization and Sprays", Hemisphere Publishing Cooperation, New York, 1989 ,

wo hingegen sich die Ohnesorge-Zahl wie folgt ergibt:

The Reynolds number is given below as follows:

where, on the other hand, the fatality number is as follows:

Furthermore, the physical model may include different sputtering models, in which, depending on different beam calculations, the initial conditions such as droplet size distribution and propagation direction of the droplets different approaches are possible. For example, a corresponding model specially adapted to the injector may have been tested or determined and adapted in experiments. For this purpose, for example, a measured drop size distribution can be used as an initial condition to a nozzle used in the internal combustion engine. In addition, there is also the possibility of a Model to incorporate, as for example Schneider, "For Modeling the Atomization of Liquid Free Radiation, Dissertation, University of Dortmund, 1995 evident. Here, an adaptation of resulting droplet size distributions has taken place in the physical model. If one proceeds from this, the length of a liquid core, as it exists in the injection jet, can be calculated, for example, on the basis of a nozzle diameter and a density ratio. For example, the following formula can be used:

Assuming that a diameter of the liquid core decreases with the distance from the nozzle, preferably decreases linearly, in addition, it is assumed that a core diameter at a tip of the liquid jet at least approximately corresponds to the diameter of a resulting secondary droplet, a diameter of this secondary drop can turn are determined from a respective nozzle pitch and from an equilibrium of forces between an aerodynamic shear force and a surface force. For this purpose, for example, the following formula can be used:

Here, a dimensionless velocity gradient calculation α as well as a relative velocity w between the liquid core and the gas as well as a radial velocity gradient as a function of the nozzle spacing are calculated. More details on the derivation of this formula can be found in the above-mentioned dissertation. This makes it possible to calculate a diameter of the liquid core at the tip and a diameter of the secondary droplet in a time-resolved manner.

Another, for example, in the physical model considered process can affect the evaporation of the fuel in the combustion chamber. The evaporation of the fuel as well as its distribution in the combustion chamber can in particular affect the ignitability of the present mixture but also the subsequent combustion. The evaporation in the form of an evaporation rate is detected or determined in the model, for example, by taking into account the temperature, velocity and pressure of the gas, on the other hand the chemical and physical properties of the fuel and the drop size distribution.

The ignitability of the injected fuel thus depends in particular on an evaporation time of a drop of the fuel, which in turn depends on the initial and boundary conditions such as diameter, pressure, temperature, relative velocity between droplets and gas and the material properties. It has been shown that at the ambient conditions in the combustion chamber, ie at gas temperatures, for example above 400 degrees Celsius and pressures of over 16 bar transport operations inside the drop are not negligible, if possible, to obtain a higher accuracy. A development therefore provides for the physical model that in the calculation of the injection jet, a drop model is used, which preferably takes into account heat conduction and diffusion resistances in the drop. However, in order to be able to calculate various possibilities with the available calculation time in a CPU of the vehicle, a simplified calculation is preferably used. For example, idealized prerequisites for this can also be assumed in order to incorporate these states into the physical model.

One embodiment provides, for example, that the material and energy flows passing between the liquid and gas phases are provided by a simplified solution of the conservation equation in the gas boundary layer with introduction of an idealized gas environment. This is based on a drop model in which the passing mass flow m. as the sum of the mass flows of the individual components m. _i understood: m. _i = ε · _i m. = ρ _q · D _{i, q} · π · D · Sh _i · ln (1 + B _i )

Here, the Sherwood number for a sphere is used as follows: Sh _i = 2 + 0.6 * Re ^1/2 * Sc _i ^1/3

More about the mass construction as well as the approach of the solution on the Sherwood number can be found in Bird, Stewart and Lightfoot, "Transport Phenomena", Wiley Publishing, New York, 1960 ,

Preferably, a diffusion coefficient is also used in the model in order to take account of corresponding influences. Preferably, this is taken from a table that is deposited for the fuel to be fueled of the vehicle. In particular, in the case of two-component or multi-component fuels, this facilitates the calculation, since otherwise such a determination of the diffusion coefficient would only be possible via iterative calculation steps. But for the application in the vehicle itself is too time-critical. Therefore, if necessary, iterative steps in the Scope of the physical model as small as possible, preferably not be made at all.

Furthermore, the physical model can take into account the heat flow transferred to the droplets within the combustion chamber by describing this convective heat flow as follows: Q. _c = π × D ² × h _c × (T _{g, ∞} -T _{g, s} )

The heat transfer coefficient h _c can be determined for example from the empirical Nusselt law for balls. It can also be stored as a table value. It is possible to provide a film correction to account for mass transfer.

As already explained above, for example, an idealized state can be considered in which, for example, the transport processes inside the droplet are not detected in detail. In such a case, consideration of the phase boundary and transport processes at the gas boundary layer may be perfectly adequate for the physical model. Then an energy balance around a drop can be formulated as follows:

Assuming an adiabatic temperature, an equation for determining the droplet temperature after a time step Δt can thus be given as follows:

At this time step .DELTA.t, furthermore, the mass concentration of these components I in the droplet is given, for example in the context of a material balance for one of the components of the fuel, as follows:

Especially with fuels from different components, the consideration of a main component alone in a simplified calculation in the model can be reflected in the model.

The above-described as well as further different quantities and formulas, which may be reflected in the physical model, are derived, for example, from a basic investigation in the form of the Final report of the German Sonderforschungsbereich 224 with the title "Motorische Verbrennungs", which can be found on the Internet under http://www.sfb224.rwth-aachen.de/bericht.htm can be viewed and referred to in connection with the disclosure of the invention in this regard.

As stated above, the penetration depth as well as the droplet size can be used as a guide to the ignitability of the injected fuel. One possibility in the context of the physical model is that a calculation of at least these variables takes place at a time Δt and it can be determined in a comparison with predetermined values whether the calculated quantities are in a target window for sufficient ignitability of the fuel or whether one or more of these values are outside of this target window. A further embodiment provides, for example, that the individual values or, within this target window, the values of quality factors are assigned, so that furthermore the evaluation of the results from the physical model can be carried out by using a sufficient quality of the ignitability.

According to one refinement, the method is preferably based on one or more fuel data, by way of which fuel properties are determined by calculations and / or calls to table values stored in the data memory and enter into the use of the physical model.

In this case, a data memory is provided which is provided with table values and / or data records, such as combustion data records or material properties, which contain calculation variables which can be called up depending on the operating point or currently used fuel quality. For example, it is possible to determine the stoichiometric air demand and the enthalpy of vaporization, which then enter into the use of the physical model.

In accordance with another aspect of the invention, which may be continued depending as well as independently of the above method, a motor controller is proposed. This has at least one data storage unit with stored table values and / or data, a control unit, an operation optimization function, a stored physical model of a mixture formation, a fuel quality detection means, a unit for data inputs, a connection for the transmission of data from Fuel quality detection means to the control unit, a unit for data outputs with interfaces to at least one actuator for the setting of at least one operating parameter, at least one interface for a management of the engine control for different fuel qualities, a computer unit for calculating and subsequent assessment of mixture formation based on the stored physical model and based data derived from the fuel quality detection means at an operating point selected by the operator of the motor vehicle, comprising a selection of operating parameters to control a fuel supply to a combustion chamber of a direct injection internal combustion engine of a motor vehicle depending on a result of the evaluation of the mixture ignition capability.

This engine control comprises a determination of the fuel property with table values stored in the data memory and / or by calculation. These may be enthalpies of the fuel, specific properties such as ignition temperature, vaporization temperature or else an indication of mixing proportions of various components together with respective data on the individual components.

Furthermore, a physical model for the calculation of the mixture formation is provided for the engine control. Here, a model can be implemented, as described in more detail above and below.

A development sees an update function, an interface for loading and / or dubbing the data in the data memory and / or the table values, with which the engine control can also be used for different fuels.

In accordance with another aspect of the invention, there is provided a computer program product having program code means stored on a computer readable medium for performing a method as described above according to at least one of the described features when the program is run on a computer and / or controller of a vehicle.

Further advantageous embodiments and developments will become apparent from the following figures. However, the embodiments shown there are not limiting, but exemplary. Individual or multiple features of an embodiment can also be detached from it with other features of another embodiment as linked to further developments from the above description. Show it:

1 an exemplary structure of an engine control method,

2 a schematic view of a proposed engine control

three a first representation of a possible test of the ignitability of a fuel,

4 another illustration of a possible test of the ignitability of the fuel, and

5 a third representation of a possible test of the ignitability of another fuel.

1 shows a structure of a described engine control method. This is a fuel quality 4 from a fuel quality detection means three determines which fuel data 5 outputs the measured quantities according to the fuel quality 4 mark. This fuel data 5 can both directly to a motor control 1 but also go into a physical model 7 a, on the basis of which the engine control 1 a mixture formation 6 calculated and then a Gemischzündfähigkeit 8th assessed. In addition to the fuel data 5 holding the fuel quality detection means three are other inputs, such as environmental data 12 , such as temperature T, air pressure p, or density of air ρ and table values 11 in a data store 2 be deposited, necessary. With these table values 11 can fuel properties 10 such as the stoichiometric air demand and the enthalpy of vaporization of the fuel are determined, which in turn as input to an engine control 1 serve. After evaluation of the mixture ignition capability 8th a selection of the operating parameters to be controlled takes place 9 to ensure optimized operation at the current operating point. For this purpose, for example, injection time, injection duration, injection quantity, ignition time or quantity distribution of the fuel injection to fuel quality 4 and / or operating point to be adjusted.

2 shows a schematic view of a proposed engine control. In this case, the engine control comprises a control unit 13 each with one unit for data inputs 15 and data outputs 17 , The data of the fuel quality detecting means three are used via the unit for data inputs 15 to the control unit 13 transfer. Furthermore, a data interface 19 is provided for controlling the ECU so that the engine control can be used for different fuels and / or different load spectrums by being catapulted as needed.

Furthermore, a data storage unit 25 with stored table values 11 provided that the control unit 13 feed with data records. A computer unit 26 assesses the mixture formation 6 based on a physical model 7 and based on fuel quality detection means data three that also in the computer unit 26 be transmitted. The unit for data outputs 17 provides at least one actuator interface 18 ready to control the sizes for optimized engine operation. Actuators used are, for example, adjusting devices in the Otto internal combustion engine and its ancillary components with which the operating parameters of the combustion can be determined or regulated. In particular, valve timing or Ventilaktorikverstellelemente for variable crankshaft, injection of the fuel and the associated devices and the ignition are to be mentioned here. Depending on which fuel quality is injected into the combustion chamber, in particular the injection quantity and the ignition timing must be adjusted as well as the injection timing.

three shows as a starting point of the considerations for the physical model another relationship that shows the effect of different injection times and their effect on the mixture formation or ignition capability. Out three For this purpose, the vapor pressure curve for a fuel A is shown, plotted on the pressure in bar and the temperature in degrees Celsius. As shown by the marks in the diagram, the respectively required partial vapor pressure for forming an ignitable mixture at λ = 1 is above the vapor pressure curve for the fuel. This means that this ignitable mixture can not be formed. A partial evaporation would lower a temperature further and further complicate the mixture formation. This means that only in the subsequent compression of other fuels could evaporate. As a consequence, however, the conclusion can be drawn that there is a high probability that the fuel in the meantime has arrived at the cold combustion chamber walls and is no longer evaporated from there. This means that in the illustrated injection during the intake process with the currently scheduled injection timing, the ignitability of the mixture is not optimal.

4 shows in the diagram shown an injection during a compression phase in the upper dead center. Initially, only the air from state 1 to state 2 is compressed. Subsequently, the injection takes place. Because the required partial vapor pressure to form an ignitable mixture with λ = 1 is below the vapor pressure curve for the fuel, the fuel may also evaporate. As a result, the cylinder charge cools down to state 3. In this, the required partial vapor pressure to form the mixture with λ = 1 is still below the vapor pressure curve for the fuel. This means that this results in a reliable ignition of the entire fuel.

5 now shows in the diagram the injection during the intake process, wherein a different fuel, namely a fuel B is used. For this fuel B is the required partial vapor pressure to form an ignitable mixture at λ = 1 below the vapor pressure curve. Therefore, an injection into the suction stroke can already take place here.

With the proposed method, it is possible, thus, to different fuels considering their properties, the ignitability of the mixture so predetermined that in operation at different conditions with respect to temperatures, pressures but also other circumstances of the injection time each shift so that evaporation of the Injected fuel safely takes place in order to achieve the desired ignitable mixtures, preferably a mixture with λ = 1 can.

LIST OF REFERENCE NUMBERS

1

motor control

2

data storage

3

Fuel quality detection means

4

Fuel Quality

5

Fuel data

6

mixture formation

7

physical model

8th

Gemischzündfähigkeit

9

operating parameters

10

Fuel properties

11

table values

12

Environmental data

13

control unit

14

Operational optimization function

15

Unit for data inputs

16

connection

17

Unit for data outputs

18

Aktorikschnittstelle

19

Bedatungsschnittstelle

20

computer unit

21

Updater

22

Calculation of fuel properties

23

Interface for setting up and / or transferring data

24

actuators

25

Data storage unit

26

computer unit

QUOTES INCLUDE IN THE DESCRIPTION

This list of the documents listed by the applicant has been generated automatically and is included solely for the better information of the reader. The list is not part of the German patent or utility model application. The DPMA assumes no liability for any errors or omissions.

Cited patent literature

• DE 102009031159 B3 [0003]
• DE 10346314 A1 [0004]

Cited non-patent literature

• Lefebre entitled "Atomization and Sprays", Hemisphere Publishing Cooperation, New York, 1989. [0019]
• Schneider, "For Modeling the Atomization of Liquid Free Radiation , Dissertation, University of Dortmund, 1995 [0021]
• Bird, Stewart and Lightfoot, "Transport Phenomena", Wiley Publishing House, New York, 1960 [0028]
• Final report of the German Sonderforschungsbereich 224 entitled "Motorische Verbrennungs", which can be found on the Internet at http://www.sfb224.rwth-aachen.de/bericht.htm [0036]

Claims (8)

Method for operating-optimized control of a fuel feed into a combustion chamber of a direct-injection internal-combustion engine of a motor vehicle, the method comprising a motor control ( 1 ), a data store ( 2 ) and a fuel quality detection means ( three ), which are respectively arranged in the motor vehicle, and the fuel quality detection means ( three ) a currently used fuel quality ( 4 ) in the form of fuel data for a mixture formation ( 6 ), these fuel data ( 5 ) and this from the engine control ( 1 ) are used, the engine control the mixture formation ( 6 ) using a physical model ( 7 ), a mixture ignition capability ( 8th ) of the calculated mixture formation ( 6 ) and operating parameters to be controlled on the basis of the assessment ( 9 ) so that the mixture ignition capability ( 8th ) is ensured in an operating point desired by the operator of the motor vehicle. Method according to claim 1, characterized in that based on one or more fuel data ( 5 ) Fuel properties ( 10 ) by calculations and / or calls in the data memory ( 2 ) stored table values ( 11 ) and into the use of the physical model ( 12 ). Method according to one of claims 1 or 2, characterized in that the physical model ( 12 ) is used with different fuels of the motor vehicle. Motor control ( 1 ) comprising at least one data memory ( 2 ) with stored table values ( 11 ), a control device ( 13 ), an operation optimization function ( 14 ), a stored physical model ( 7 ) a mixture formation, a fuel quality detection means ( three ), a unit for data inputs ( 15 ), a connection ( 16 ) for transmitting data from the fuel quality detection means ( three ) to the control unit ( 13 ), a unit for data outputs ( 17 ) with at least one interface ( 18 ) to at least one actuator ( 23 ) for setting at least one operating parameter ( 9 ), at least one interface ( 19 ) of the engine control ( 1 ) for different fuel qualities ( 4 ), a computer unit ( 20 ) for the calculation and subsequent assessment of a mixture formation ( 6 ) based on the stored physical model ( 7 ) and fuel data ( 5 ) generated by the fuel quality detection means ( three ) at an operating point selected by the operator of the motor vehicle, with a selection of operating parameters to be controlled ( 9 ) for controlling a fuel supply into a combustion chamber of a direct injection internal combustion engine of a motor vehicle in dependence on a result of the assessment of the mixture ignition capability (US Pat. 8th ). Motor control ( 1 ) according to claim 4, characterized in that it has a determination of the fuel property ( 10 ) in the data memory ( 2 ) stored table values ( 11 ) and / or by calculation. Motor control ( 1 ) according to claim 4 or 5, characterized in that the physical model ( 7 ) for the calculation of mixture formation ( 6 ). Motor controller according to Claim 4, 5 or 6, characterized in that it has an updating function ( 21 ), an interface ( 22 ) for uploading and / or dubbing the data in the data memory ( 2 ) and / or the table values ( 11 ) and can be used for various fuels. A computer program product comprising program code means stored on a computer readable medium to perform a method according to at least one of claims 1 to 4 when the program is executed on a computer and / or controller of a vehicle.

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