Method for operating a fuel valve of an internal combustion engine, control device for carrying out such a method, fuel valve device with such a control device and internal combustion engine with such a fuel valve device

Abstract

The invention relates to a method for operating a fuel valve (7) of an internal combustion engine (1), wherein a target fuel mass (mtarget) for delivery through the fuel valve (7) is specified, wherein a correction parameter (k) is determined using a correction model (KM) based on the target fuel mass (mtarget), wherein a fuel valve energization duration (tBD) is determined using a fuel valve model (B) based on the target fuel mass (mtarget) and the correction parameter (k), and wherein the fuel valve (7) is controlled with the fuel valve energization duration (tBD).

Description

The invention relates to a method for operating a fuel valve of an internal combustion engine, to a control device for carrying out such a method, to a fuel valve device having such a control device and to an internal combustion engine having such a fuel valve device.It is known that in an internal combustion engine, in particular a hydrogen internal combustion engine, the fuel, in particular the hydrogen, is introduced, typically injected, fluidically upstream of a combustion chamber and / or directly into the combustion chamber via a multi-port injection valve (MPI valve). In this case, a setpoint fuel mass, in particular a setpoint hydrogen mass, is predefined per introduction process. The MPI valve is then actuated with an energization duration assigned to the predefined setpoint fuel mass in order to emit fuel. The energization time of the MPI valve is determined from a conventional nozzle equation. The conventional nozzle equation is based on an ideal valve. A disadvantage of this is that the ideal valve only partially simulates a real MPI valve. It follows from this that an actually introduced fuel mass does not correspond to the setpoint fuel mass and thus, in particular, an efficiency and / or a pollutant formation of the internal combustion engine are adversely affected.Typically, based on test bench measurements, a correction variable-in particular a correction variable characteristic diagram-is determined beforehand for the nozzle equation and permanently stored in a control device of the internal combustion engine. A disadvantage of this is that the correction variable has to be determined on a test stand in a complicated, time-consuming and cost-intensive manner. Furthermore, it is disadvantageously not possible to adapt the correction variable during operation of the internal combustion engine to aging of the fuel valve or other changing conditions.The object of the invention is therefore to provide a method for operating a fuel valve of an internal combustion engine, a control device for carrying out such a method, a fuel valve device having such a control device and an internal combustion engine having such a fuel valve device, wherein the disadvantages mentioned are at least reduced, preferably do not occur.The object is achieved by providing the present technical teaching, in particular the teaching of the independent claims and of the preferred embodiments disclosed in the dependent claims and the description.The object is achieved in particular by providing a method for operating a fuel valve of an internal combustion engine. In this case, a setpoint fuel mass is predefined for discharge by the fuel valve. Furthermore, a correction variable is determined by means of a correction model on the basis of the setpoint fuel mass-at the runtime of the method, in particular in real time. A fuel valve energization duration is determined by means of a fuel valve model on the basis of the setpoint fuel mass and the correction variable. The fuel valve is then controlled with the fuel valve energization duration. Advantageously, the determination of the correction variable is independent of a condition of the internal combustion engine. In addition, the correction model can be changed more flexibly than a permanently mapped correction variable characteristic map. Furthermore, it is thus possible to more accurately simulate a mode of operation of the fuel valve by means of the fuel valve model on the basis of the variable, in particular time-variable, correction variable.In one embodiment, the fuel valve is controlled with the fuel valve energization duration t BD in order to deliver an actual fuel mass m ist corresponding to the setpoint fuel mass m soll. The fuel valve is opened at the beginning of the fuel valve energization duration t BD over a fuel valve opening duration t o. After the energization duration t BD the fuel valve is closed-in particular driven by a closing spring, a fuel pressure difference or the like-for a fuel valve closing duration t c. Thus, starting from a starting time t=0, the fuel valve is opened in a first introduction interval [0, t o] in a second introduction interval [t o, t BD] the fuel valve is fully opened, and the fuel valve is closed in a third introduction interval [t BD, t BD+ t c].In one embodiment, a gaseous fuel, in particular hydrogen, is used as fuel. Alternatively, a liquid fuel is used as the fuel.In one configuration, a multi-port injection valve (MPI valve) is used as the fuel valve, wherein the hydrogen is injected via the MPI valve.The correction model is referred to below as K M. In this case, the correction model K M is determined in particular on the basis of at least one data point (m soll, k), wherein the correction variable is denoted by k. In one embodiment, the correction variable k is determined by means of the equation.The fuel valve model is referred to below as B. In one embodiment, the fuel valve energization duration t BD is determined by means of a first fuel valve function B 1(...) of the fuel valve model B, wherein the following applies in particular.According to a further development of the invention, it is provided that an actual fuel mass actually delivered when the fuel valve is controlled with the fuel valve energization duration is determined. By means of the fuel valve model, an adapted correction variable is determined on the basis of the actual fuel mass and the fuel valve energization duration. The correction model is then adapted on the basis of the adapted correction variable and the setpoint fuel mass. Advantageously, it is thus possible to build up the correction model automatically and, in particular, to adapt it to a change of the internal combustion engine during the operation of the internal combustion engine. Furthermore, this advantageously eliminates the need for a particularly manual determination of the correction variable based on test stand data.In one embodiment, the adjusted correction variable k a is determined by means of a second fuel valve function B 2(...) in this case, wherein the following applies in particular. In particular, the first fuel valve function B 1(...) and the second fuel valve function B 2(...) are selected such that equations (2) and (3), in particular for m soll= m ist and k=k a, can be transformed into one another-in particular equivalently.In particular, the actual fuel mass m ist and the associated adapted correction variable k a form an additional data point for the correction model K M, wherein the correction model K M is adapted on the basis of the additional data point.In one embodiment, the actual fuel mass m ist is determined by means of a fuel mass sensor.According to a further development of the invention, it is provided that a combustion air pressure, in particular a charge pressure, and / or a fuel pressure is additionally taken into account. In this case, the correction variable is additionally determined by means of the correction model as a function of the combustion air pressure and / or the fuel pressure. Furthermore, the fuel valve energization duration is additionally determined by means of the fuel valve model on the basis of the combustion air pressure and / or the fuel pressure. Advantageously, a more differentiated determination of the correction variable is possible by means of the combustion air pressure and / or the fuel pressure, so that the fuel valve can be better adapted to the operation of the internal combustion engine. In addition, a combustion chamber-individual correction variable can be determined therewith.In the context of the present technical teaching, the combustion air pressure is present in a flow direction upstream of a location of the fuel valve in terms of flow along a combustion air flow direction. In particular, the combustion air pressure is the pressure of a combustion air upstream of the fuel valve in terms of flow. In one configuration, the internal combustion engine has a combustion air compressor, in particular a compressor or an exhaust gas turbocharger. In this embodiment, the combustion air pressure corresponds to a charge pressure, wherein the charge pressure is fluidically present upstream of the location of the fuel valve along a charge air flow direction.In the context of the present teachings, the fuel pressure is the pressure of the fuel in the fuel valve.In one embodiment, the combustion air pressure is determined by means of a combustion air pressure sensor. Alternatively or additionally, the fuel pressure is determined by means of a fuel pressure sensor.In particular, the correction model K M is determined on the basis of at least one data point (m ist, k, p L, p B). In one embodiment, the correction variable k is determined by means of the equation, wherein p L denotes the combustion air pressure and p B denotes the fuel pressure.In particular, the first fuel valve function B 1(...) of the fuel valve model B for determining the fuel valve energization duration t BD is additionally dependent on the combustion air pressure p L and the fuel pressure p B, wherein the following applies in particular.In one embodiment, in equation (6), the combustion air pressure p L and the fuel pressure p B enter the first fuel valve function B 1(...) via an outflow function ψ(p L, p B). In this case, the equation applies in particular to the outflow function ψ( PL, p B) wherein κ denotes an adiabatic exponent of the fuel and a predetermined pressure ratio. Specifically, the predetermined pressure ratio is determined from the equation.In a configuration in which hydrogen is used as the fuel, κ=1.4.According to a further development of the invention, it is provided that the adjusted correction variable is additionally determined by means of the fuel valve model on the basis of the combustion air pressure and / or the fuel pressure. In addition, the correction model is adapted on the basis of the combustion air pressure and / or the fuel pressure. Advantageously, a more differentiated determination of the adapted correction variable is possible by means of the combustion air pressure and / or the fuel pressure. Furthermore, the correction model can be adapted more comprehensively by means of the combustion air pressure and / or the fuel pressure.In particular, the second fuel valve function B 2(...) of the fuel valve model B for determining the adjusted correction variable k a is additionally dependent on the combustion air pressure p L and the fuel pressure p B, wherein the following applies in particular. In particular, the first fuel valve function B 1(...) and the second fuel valve function B 2(...) are selected such that equations (6) and (10), in particular for m soll= m ist and k=k a, can be transformed into one another-in particular equivalently.In particular, the actual fuel mass m ist and the associated adapted correction variable k a form an additional data point for the correction model K M, wherein the correction model K M is adapted on the basis of the additional data point.According to a further development of the invention, it is provided that by means of the fuel valve model, the fuel valve energization duration is additionally determined on the basis of at least one parameter selected from a group consisting of a flow coefficient, an opening area, the fuel valve opening duration, the fuel valve closing duration, a fuel temperature, a specific gas constant, and any combination of at least two of the preceding parameters.In the context of the present technical teaching, the flow coefficient c d is a dimensionless characteristic number having a value of 0 to 1, which specifies how unhindered the fuel can flow in the internal combustion engine-in particular the fuel valve. In particular, the flow coefficient c d is influenced by a geometry of the fuel valve. In this case, under otherwise identical conditions, more fuel per unit time-in particular a greater mass flow-flows through the fuel valve, the greater the flow coefficient. Alternatively or additionally, it applies that a first mass flow of the fuel in the fuel valve having a first flow coefficient is greater than a second mass flow of the fuel in the fuel valve having a second flow coefficient if--in otherwise identical conditions--the first flow coefficient is greater than the second flow coefficient.In the context of the present technical teaching, the opening area A is a cross-sectional area of the fuel valve at the point at which the fuel exits the fuel valve and is introduced in particular into the combustion air, in particular the charge air, of the internal combustion engine. In one embodiment, the opening area A is time-dependent, wherein the opening area increases in the first introduction interval [0, t o] - in particular from 0 m 2 to a maximum opening area A o-, wherein the opening area A remains constant in the second introduction interval [t o, t BD] - in particular maintains the maximum opening area A o - and wherein the opening area A decreases in the third introduction interval [t BD, t BD+ t c] - in particular from the maximum opening area A o to 0 m2.In the context of the present technical teaching, the fuel temperature T B is an absolute temperature of the fuel-measured in Kelvin-in an interior of the fuel valve.In the context of the present technical teaching, the specific gas constant R B is calculated on the basis of the equation, where R I denotes the ideal gas constant-in particular applies-and M B denotes an average molar mass of the fuel. In the embodiment in which hydrogen is used as fuel, H 2. applies to molecular hydrogen. Thus, for the specific gas constant R, B applies to hydrogen according to equation (12)In particular, the first fuel valve function B 1(...) of the fuel valve model B for determining the fuel valve energization duration t BD is additionally dependent on the flow coefficient c d, the opening area A, the fuel valve opening duration t o, the fuel valve closing duration t c, the fuel temperature T B and the specific gas constant R B, wherein the following applies in particular.According to a further development of the invention, it is provided that by means of the fuel valve model, the adjusted correction variable is additionally determined on the basis of at least one parameter selected from a group consisting of the flow coefficient, the opening area, the fuel valve opening duration, the fuel valve closing duration, the fuel temperature, the specific gas constant, and any combination of at least two of the preceding parameters.In particular, the second fuel valve function B 2(...) of the fuel valve model B for determining the adjusted correction variable k a is additionally dependent on the flow coefficient c d, the opening area A, the fuel valve opening duration t o, the fuel valve closing duration t c, the fuel temperature T B and the specific gas constant R B, wherein the following applies in particular. In particular, the first fuel valve function B 1(...) and the second fuel valve function B 2(...) are selected such that equations (13) and (14), in particular for m soll= m ist and k=k a, can be transformed into one another-in particular equivalently.According to a further development of the invention, it is provided that a Gaussian process model is used as the correction model. Gaussian process models are particularly suitable for forming a correction model: in comparison with polynomial-based models, they are particularly easier to adapt to new or modified data points in the field of application, and they have a more suitable and also more physically correct behavior in edge regions of the given parameter space. Compared to physical models, they require a significantly lower computational effort. In addition, they enable the direct use of test bench data. Such a Gaussian process model is constructed and / or refined in particular on the basis of stored data points (X b, Y b) obtained, for example, in test bench tests and / or in real operation of the internal combustion engine, wherein X b ∈R ixj in particular i, indicates input variables for j different operating states and Y b ∈R ixn in particular n, indicates output variables for the j different operating states. In one embodiment, j=1 applies in a first step, j being increased by 1 in each iteration step of the measurement of the internal combustion engine. In an alternative embodiment, a basic grating of the Gaussian process model, in particular j operating states, is known, and on the basis of new further operating states, in particular new input variables and associated output variables, the basic grating of the Gaussian process model is refined and / or adapted, wherein j is increased by 1 in each iteration step of the measurement of the internal combustion engine. In particular, the input variables X b form a subset of the union set of the setpoint fuel mass m soll, the combustion air pressure p L and the fuel pressure p B, such that in particular i≤3, particularly preferably i=3, applies. The output variable Y b is the correction variable k, so that in particular n=1 applies. Furthermore, the Gaussian process model is given by a predefined calculation scheme for an expected value E(X u) ∈R o×n and a variance Var(X u) ∈R o×o for input variables not contained in the original data set for o different operating states X u ∈R i×o: with an average value function m(X u) and a covariance function K, which is calculated in the following manner from the Euclidean distance r between two points x r, x s depends: with a predetermined distance parameter l-in particular a width of a Gaussian bell-, a predetermined signal variance σ F- in particular a predetermined signal swing-, a predetermined measurement noise σ N and the Kronecker delta δ r,s. In particular, δ r,s= 0 applies to two different points x r, x s and δ r,s= 1 applies to two identical points x r, x s, whereby advantageously a numerical calculation of the function K(·,·) becomes more stable, in particular a numerical calculation of an inverse becomes more stable. Furthermore, |||| 2 refers in particular to the Euclidean norm or 2 norm. Thus, in equations (15) and (16), K(X u, X b) ∈R o×j, K(X b, x b) ∈ j×j, K(X u, X u) ∈R o×o and K(X b, Xu) ∈Rj×NER141_appear.For the mean value function m(X u) preferably m(X u)=1 is set.In one embodiment, the correction variable k is then determined on the basis of the equations (5) and (15) on the basis of the equation.According to a further development of the invention, it is provided that a nozzle equation is used as the fuel valve model. Advantageously, a more accurate modelling of the fuel valve is thus possible in a simple and rapid manner.In particular, the nozzle equation describes a time-varying change of a time-varying fuel mass m(t) on the basis of the equation with a time-varying opening area A(t). This applies to a fuel mass per introduction interval [0, t BD+ t c] of the fuel valve, wherein A*(t) denotes the basic function of the opening area A(t) which varies over time.In particular, for the determination of the fuel valve energization duration t BD for the fuel mass m=m soll is set and equation (22) is changed over to t BD.Alternatively or additionally, for the determination of the adjusted correction variable k a for the fuel mass m=m ist and for the correction variable k=k a is set and equation (22) is changed over to k a.In one embodiment, the time-varying opening area A(t) of the fuel valve is determined based on the equation. The integral from equation (22) can thus be determined as being, wherein the value of the integral can likewise be used in equations (22) to (24). This applies to the determination of the fuel valve energization duration t BD on the basis of equations (23) and (26), and to the determination of the adapted correction variable k a on the basis of equations (24) and (26)The method is particularly preferably carried out cyclically, in particular at a frequency of 0.01 Hz to 1 Hz. Alternatively or additionally, the method is carried out with a predetermined time interval in operating hours. Alternatively or additionally, the method is carried out under event control.The object is also achieved by providing a control device which is set up to carry out a method according to the invention or a method according to one or more of the embodiments described above. The control device is preferably designed as a computing device, particularly preferably as a computer, or as a control device, in particular as a control device of an internal combustion engine. In connection with the control device, the advantages are obtained in particular, which have already been explained in connection with the method.The control device is in particular configured to be connected to the fuel valve and configured to actuate it. Alternatively or additionally, the control device is configured to be connected to the combustion air pressure sensor and / or the fuel pressure sensor. Alternatively or additionally, the control device is configured to be connected to the fuel mass sensor.The object is also achieved by providing a fuel valve device having a fuel valve and a control device according to the invention or a control device according to one or more of the embodiments described above. In connection with the fuel valve device, there are in particular the advantages which have already been explained in connection with the method and the regulating device.In particular, the fuel valve is an MPI valve. Alternatively or additionally, the fuel is a gaseous fuel, in particular hydrogen, or a liquid fuel.In particular, the fuel valve device additionally has the combustion air pressure sensor. Alternatively or additionally, the fuel valve device has the fuel pressure sensor. Alternatively or additionally, the fuel valve device has the fuel mass sensor.The control device is operatively connected in particular to the fuel valve and is configured to actuate it. Alternatively or additionally, the control device is operatively connected to the combustion air pressure sensor and / or the fuel pressure sensor. Alternatively or additionally, the control device is operatively connected to the fuel mass sensor.The object is finally also achieved by providing an internal combustion engine having at least one combustion chamber, an inlet valve assigned to the at least one combustion chamber and a fuel valve device according to the invention or a fuel valve device according to one or more of the embodiments described above. In this case, a fuel valve of the fuel valve device is arranged upstream of an inlet valve in terms of flow along a combustion air flow direction, in particular a charge air flow direction. In connection with the internal combustion engine, there are in particular the advantages which have already been explained in connection with the method, the control device and the fuel valve device.The invention is explained in more detail below with reference to the drawings. The following are shown: FIG. 1 shows a schematic illustration of an exemplary embodiment of an internal combustion engine, and FIG. 2 shows a flow chart of an exemplary embodiment of a method for operating a fuel valve of the internal combustion engine.FIG. 1 shows a schematic illustration of an exemplary embodiment of an internal combustion engine 1. the internal combustion engine 1 has a fuel valve device 3 and at least one combustion chamber 5. The fuel valve device 3 has a fuel valve 7 and a control device 9. The control device 9 is operatively connected to the fuel valve 7 and is configured to actuate it. Combustion chamber 5 also has an inlet valve 11.1 and an outlet valve 11.2. The fuel valve device 3 is arranged upstream of the inlet valve 11.1 in terms of flow along a combustion air flow direction 13, in particular a charge air flow direction 13. Furthermore, an exhaust gas flow direction 14 is shown.Particularly preferably, the fuel valve device 3 additionally has a combustion air pressure sensor 15, in particular a charge pressure sensor 15, and / or a fuel pressure sensor 17. In this case, the combustion air pressure sensor 15 is configured to determine a combustion air pressure p L, in particular a charge pressure p L, directly or indirectly. Alternatively or additionally, the fuel pressure sensor 17 is configured to determine a fuel pressure p B directly or indirectly. Alternatively or additionally, the fuel valve device 3 has a fuel mass sensor 19 which is configured to determine an actual fuel mass m ist directly or indirectly. Alternatively or additionally, the control device 9 is operatively connected to the combustion air pressure sensor 15 and / or the fuel pressure sensor 17. Alternatively or additionally, the control device 9 is operatively connected to the fuel mass sensor 19.The control device 9 is configured in particular to carry out a method for operating the fuel valve 7 of the internal combustion engine 1 according to one or more of the exemplary embodiments described below.FIG. 2 shows a flow chart of an exemplary embodiment of a method for operating the fuel valve 7 of the internal combustion engine 1 according to FIG. 1.Identical and functionally identical elements are provided with the same reference symbols in all figures, so that reference is made to the preceding description in each case in this respect.For the sake of clearer illustration, the flow arrows to steps S 1 to S 4 are illustrated as solid arrows. In contrast, the flow arrows to steps S 6 and S 7 are shown as dashed arrows. In addition, intermediate arrows were inserted to make the flow directions more easily recognizable.In a first step S 1, a setpoint fuel mass m soll is predefined for delivery through the fuel valve.In a second step S 2, a correction variable k is determined by means of a correction model K M on the basis of the setpoint fuel mass m soll. In one embodiment, the correction variable k is determined by means of the equation (1). In particular, in the second step S 2, the combustion air pressure p L is additionally taken into account in order to determine the correction variable k by means of the correction model K M. In a particularly preferred embodiment, equation (5) is used to determine the correction variable k.In particular, the correction model K M is determined on the basis of at least one data point (m ist, k). Fuel pressure p B is preferably taken into account in order to determine correction variable k by means of correction model K M. Particularly preferably, the correction model K M is determined on the basis of at least one data point (m ist, k, P L, P B). Particularly preferably, a Gaussian process model is used as the correction model K M - in particular according to equations (15) to (19). In one embodiment, the correction variable k is then determined on the basis of the equations (5) and (15) on the basis of the equation (20).In a third step S 3, a fuel valve energization duration t BD is determined by means of a fuel valve model B on the basis of the setpoint fuel mass m soll and the correction variable k. Specifically, the fuel valve energization time t BD is determined by the equation (2).In particular, in the third step S 3, the combustion air pressure p L is additionally taken into account in order to determine the fuel valve energization duration t BD by means of the fuel valve model B. Alternatively or additionally, the fuel pressure p B is additionally taken into account in order to determine the fuel valve energization duration t BD by means of the fuel valve model B. Specifically, the fuel valve energization time t BD is determined by the equation (6). Preferably, the combustion air pressure p L and the fuel pressure p B enter the fuel valve model B according to equation (6) via an outflow function ψ(p L, p B) according to equation (7)-in particular equations (8) and (9) in the case of hydrogen as fuel.In particular, in the third step S 3, at least one parameter 21, selected from a group consisting of a flow coefficient C d, an opening area A, a fuel valve opening duration t o, a fuel valve closing duration t c, a fuel temperature T B, a specific gas constant R B, and any combination of at least two of the preceding parameters 21, is additionally taken into account in order to determine the fuel valve energization duration t BD by means of the fuel valve model B. Specifically, the fuel valve energization time t BD is determined by the equation (13).In a fourth step S 4, the fuel valve 7 is actuated with the fuel valve energization duration t BD. In particular, the fuel valve 7 is controlled with the fuel valve energization duration t BD in order to deliver an actual fuel mass corresponding to the setpoint fuel mass m soll. In particular, the fuel valve 7 is opened and / or remains open during an energization-in particular the fuel valve energization duration t BD-. At this time, the fuel valve 7 is opened for the fuel valve opening period t o. In addition, the fuel valve 7 is closed for the fuel valve closing period t c. The fuel valve 7 is thus opened in a first introduction interval [0, t o] in a second introduction interval [t o, t BD] in the fuel valve 7 is opened and the fuel valve 7 is closed in a third introduction interval [t BD, t BD+ t c] in the fuel valve 7.In an optional fifth step S 5, the actual fuel mass m ist actually emitted when the fuel valve 7 is activated with the fuel valve energization duration t BD is determined. In particular, the actual fuel mass m ist is determined directly or indirectly by means of the fuel mass sensor 19.In an optional sixth step S 6, an adjusted correction variable k a is determined by means of the fuel valve model B on the basis of the actual fuel mass m ist and the fuel valve energization duration t BD. In particular, the adjusted correction variable k a is determined by means of the equation (3).In particular, in the sixth step S 6, the combustion air pressure p L is additionally taken into account in order to determine the adapted correction variable k a by means of the fuel valve model B. Alternatively or additionally, the fuel pressure p B is taken into account in order to determine the adapted correction variable k a by means of the fuel valve model B. In particular, the adjusted correction variable k a is determined by means of the equation (10).In particular, in the sixth step S 6, the at least one parameter 21, selected from a group consisting of the flow coefficient c d, the opening area A, the fuel valve opening duration t o, the fuel valve closing duration t c, the fuel temperature T B, the specific gas constant R B, and any combination of at least two of the preceding parameters 21, is additionally taken into account in order to determine the adapted correction variable k a by means of the fuel valve model B. In particular, the adjusted correction variable k a is determined by means of the equation (14).Particularly preferably, in the third step S 3 and / or the sixth step S 6, a nozzle equation according to equations (21) to (24) is used as the fuel valve model B. In particular, the fuel valve model B is simplified in the case of a temporally variable opening area A(t) of the fuel valve according to equation (25), and the fuel valve energization duration t BD is determined by means of equation (27) and the adapted correction variable k a is determined by means of equation (28).In an optional seventh step S 7, the correction model K M is adjusted on the basis of the adjusted correction variable k a and the actual fuel mass m ist. In particular, the actual fuel mass m ist and the associated adapted correction variable k a form an additional data point according to equation (4) for the correction model K M, wherein the correction model K M is adapted on the basis of the additional data point.In particular, in the seventh step S 7, the correction model K M is additionally adapted on the basis of the combustion air pressure p L. Alternatively or additionally, the correction model K M is additionally adapted on the basis of the fuel pressure p B. In particular, the actual fuel mass m ist, the associated adapted correction variable k a, the associated combustion air pressure p L and the associated fuel pressure p B form an additional data point according to equation (11) for the correction model K M, wherein the correction model K M is adapted on the basis of the additional data point.In an optional eighth step S 8, the combustion air pressure p L is determined. In particular, the combustion air pressure p L is determined directly or indirectly by means of the combustion air pressure sensor 15.In an optional ninth step S 9, the fuel pressure p B is determined. In particular, the fuel pressure p B is determined directly or indirectly by means of the fuel pressure sensor 17.

Claims

Method for operating a fuel valve (7) of an internal combustion engine (1), wherein - a setpoint fuel mass (m soll) is specified for delivery by the fuel valve (7), wherein - a correction variable (k) is determined by means of a correction model (K M) on the basis of the setpoint fuel mass (m soll) wherein - a fuel valve energization duration (t BD) is determined by means of a fuel valve model (B) on the basis of the setpoint fuel mass (m soll) and the correction variable (k), wherein - the fuel valve (7) is actuated with the fuel valve energization duration (t BD).Method according to Claim 1, wherein - an actual fuel mass (m ist) actually emitted when the fuel valve (7) is activated with the fuel valve energization duration (t BD) is determined, wherein - an adapted correction variable (k a) is determined by means of the fuel valve model (B) on the basis of the actual fuel mass (m ist) and the fuel valve energization duration (t BD) and - the correction model (K M) is adapted on the basis of the adapted correction variable (k a) and the actual fuel mass (m ist).Method according to one of the preceding claims, wherein - the correction variable (k) is additionally determined by means of the correction model (K M) as a function of a combustion air pressure (p L) and / or a fuel pressure (p B) wherein - the fuel valve energization duration (t BD) is additionally determined by means of the fuel valve model (B) on the basis of the combustion air pressure (p L) and / or the fuel pressure (p B).Method according to Claims 2 and 3, wherein - the adjusted correction variable (k a) is additionally determined by means of the fuel valve model (B) on the basis of the combustion air pressure (p L) and / or the fuel pressure (P B) wherein - the correction model (K M) is additionally adjusted on the basis of the combustion air pressure (P L) and / or the fuel pressure (p B).Method according to one of the preceding claims, wherein the fuel valve energization duration (t BD) is additionally determined by means of the fuel valve model (B) on the basis of at least one parameter (21) selected from a group consisting of a flow coefficient (c d), an opening area (A), a fuel valve opening duration (t o), a fuel valve closing duration (t c), a fuel temperature (T B), a specific gas constant (R B), and any combination of at least two of the preceding parameters (21).Method according to one of the preceding claims, wherein the adjusted correction variable (k a) is additionally determined by means of the fuel valve model (B) on the basis of at least one parameter (21) selected from a group consisting of the flow coefficient (c d), the opening area (A), the fuel valve opening duration (t o), the fuel valve closing duration (t c), the fuel temperature (T B), the specific gas constant (R B), and any combination of at least two of the preceding parameters (21).Method according to one of the preceding claims, wherein a Gaussian process model is used as the correction model (K M).Method according to one of the preceding claims, wherein a nozzle equation is used as the fuel valve model (B).Control device (9) for carrying out a method according to one of the preceding claims.Fuel valve device (3) comprising a fuel valve (7) and a control device (9) according to claim 9.Internal combustion engine (1) having at least one combustion chamber (5), an inlet valve (11.1) assigned to the at least one combustion chamber and a fuel valve device (3) according to Claim 10, wherein the fuel valve (7) is arranged upstream of an inlet valve (11.1) in terms of flow along a combustion air flow direction (13).

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