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

Method for operating a fuel valve (7) of an internal combustion engine (1), wherein - a target fuel mass (m soll ) is specified for delivery through the fuel valve (7), whereby - using a correction model (K M ) based on the target fuel mass (m soll ) a correction value (k) is determined, where - by means of a fuel valve model (B) based on the target fuel mass (m soll ) and the correction value (k) a fuel valve energization time (t BD ), where - the fuel valve (7) with the fuel valve energization duration (t BD ) is controlled.

Description

[0001] The invention relates to 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 with such a control device and an internal combustion engine with such a fuel valve device.

[0002] It is known that in an internal combustion engine, particularly a hydrogen internal combustion engine, the fuel, particularly hydrogen, is introduced, typically injected, via a multiport injection valve (MPI valve) in front of a combustion chamber and / or directly into the combustion chamber. A target fuel mass, particularly a target hydrogen mass, is specified for each injection process. The MPI valve is then actuated with an energization duration associated with the specified target fuel mass in order to deliver fuel. The energization duration of the MPI valve is determined using a conventional nozzle equation. The conventional nozzle equation is based on an ideal valve. The disadvantage of this is that the ideal valve only partially replicates a real MPI valve.This means that the actual fuel mass introduced does not correspond to the target fuel mass and thus, in particular, the efficiency and / or pollutant formation of the internal combustion engine is adversely affected.

[0003] Typically, a correction variable—specifically, a correction variable map—for the nozzle equation is determined in advance based on test bench measurements and permanently stored in a control unit of the internal combustion engine. The disadvantage of this is that the correction variable must be determined on a test bench, which is complex, time-consuming, and costly. Furthermore, it is not possible to adapt the correction variable to fuel valve aging or other changing conditions during operation of the internal combustion engine.

[0004] DE 10 2018 208 712 A1 discloses a method for operating a fuel valve of an internal combustion engine, in which multiple fuel injections are delivered by the fuel valve, wherein the fuel injections have different injection start delays. A value characteristic of the injection start is determined from a sensor signal of a needle closure sensor of the fuel valve for each injection start delay. Furthermore, for each injection start delay, a difference between the determined characteristic value and an expected value is calculated, wherein the expected value can be derived from a model. A correction function for the injection start is determined from these differences. This correction function can then be used in the further operation of the fuel valve to correct deviations between the determined injection start and the true injection start.

[0005] Further methods for operating fuel valves are also disclosed in DE 10 2013 217 803 B4 and DE 10 2013 211 731 A1.

[0006] The invention is therefore based on the object of providing 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 with such a control device and an internal combustion engine with such a fuel valve device, wherein the disadvantages mentioned are at least reduced, preferably do not occur.

[0007] The object is achieved by providing the present technical teaching, in particular the teaching of the independent claims as well as the preferred embodiments disclosed in the dependent claims and the description.

[0008] The object is achieved in particular by providing a method for operating a fuel valve of an internal combustion engine. In this case, a target fuel mass for delivery through the fuel valve is specified. Furthermore, a correction variable is determined using a correction model based on the target fuel mass - during the runtime of the method, in particular in real time. Using a fuel valve model, a fuel valve energization duration is determined based on the target fuel mass and the correction variable. The fuel valve is then controlled using the fuel valve energization duration. Advantageously, the determination of the correction variable is independent of any parameterization of the internal combustion engine. Furthermore, the correction model can be changed more flexibly than a fixed-data correction variable map.Furthermore, it is possible to more accurately simulate the functioning of the fuel valve using the fuel valve model based on the more variable, in particular time-varying, correction variable.

[0009] In one embodiment, the fuel valve is energized with the fuel valve energization duration t BD controlled to achieve one of the target fuel mass m soll corresponding actual fuel mass m ist The fuel valve is opened at the beginning of the fuel valve energization period t BD over a fuel valve opening time t o opened. After the current application time t BD the fuel valve is driven - in particular by a closing spring, a fuel pressure difference or the like - for a fuel valve closing duration t c closed. Starting from a starting time t = 0, the fuel valve is then closed in a first injection interval [0,t o] opened, in a second insertion interval [t o ,t BD ] the fuel valve is fully open, and in a third injection interval [t BD ,t BD + t c ] the fuel valve is closed.

[0010] In one embodiment, a gaseous fuel, in particular hydrogen, is used as the fuel. Alternatively, a liquid fuel is used as the fuel.

[0011] In one embodiment, a multiport injection valve (MPI valve) is used as the fuel valve, with the hydrogen being injected via the MPI valve.

[0012] The correction model is referred to below as K M The correction model K M in particular based on at least one data point (m soll , k), where the correction value is denoted by k. In one embodiment, the correction value k is determined using the equation k=KM(msoll) certainly.

[0013] The fuel valve model is referred to below as B. In one embodiment, the fuel valve energization time t BD by means of a first fuel valve function B1(...) of the fuel valve model B, wherein in particular tBD=B1(msoll,k) applies.

[0014] According to a further development of the invention, the actual fuel mass actually delivered when the fuel valve is actuated with the fuel valve energization duration is determined. Using the fuel valve model, an adjusted correction variable is determined based on the actual fuel mass and the fuel valve energization duration. The correction model is then adjusted based on the adjusted correction variable and the target fuel mass. This advantageously makes it possible to automatically construct the correction model and, in particular, to adapt it to a change in the internal combustion engine during operation. Furthermore, this advantageously eliminates the need for manual determination of the correction variable based on test bench data.

[0015] In one embodiment, the adjusted correction value k aby means of a second fuel valve function B2(...), wherein in particular ka=B2(mist,tBD) In particular, the first fuel valve function B1(...) and the second fuel valve function B2(...) are selected such that equations (2) and (3), in particular for m soll = m ist and k = k a , are transformable into one another - in particular equivalent.

[0016] In particular, the actual fuel mass m ist and the corresponding adjusted correction value k a an additional data point (mist,k=ka=B2(mist,tBD)) for the correction model K M , where the correction model K M adjusted based on the additional data point.

[0017] In one embodiment, the actual fuel mass m ist determined using a fuel mass sensor.

[0018] According to a further development of the invention, it is provided that a combustion air pressure, in particular a boost 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 based on the combustion air pressure and / or the fuel pressure. Advantageously, a more differentiated determination of the correction variable is possible using 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-specific correction variable can thus be determined.

[0019] In the context of the present technical teaching, the combustion air pressure is present fluidically upstream of a location of the fuel valve along a combustion air flow direction. In particular, the combustion air pressure is the pressure of combustion air fluidically upstream of the fuel valve. In one embodiment, 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 boost pressure, wherein the boost pressure is present fluidically upstream of the location of the fuel valve along a charge air flow direction.

[0020] In the context of the present technical teaching, the fuel pressure is the pressure of the fuel in the fuel valve.

[0021] In one embodiment, the combustion air pressure is determined using a combustion air pressure sensor. Alternatively or additionally, the fuel pressure is determined using a fuel pressure sensor.

[0022] In particular, the correction model K M based on at least one data point (m ist , k, p L , p B ). In one embodiment, the correction value k is determined using the equation k=KM(mist,pL,pB) determined, where p L the combustion air pressure and with p B which is called the fuel pressure.

[0023] In particular, the first fuel valve function B1(...) of the fuel valve model B is used to determine the fuel valve energization duration t BD additionally dependent on the combustion air pressure p L and the fuel pressure p B , in particular tBD=B1(msoll,k,pL,PB) applies.

[0024] In one embodiment, equation (6) includes the combustion air pressure p L and the fuel pressure p B via an outflow function ψ(p L , p B ) into the first fuel valve function B1(...). The discharge function ψ(p L , p B ) in particular the equation ψ(pL,pB)={(2κ+1)1κ−1⋅κκ+1,if (pLpB)<(pLpB)criticalκκ−1[(pLpB)2κ−(pLpB)κ+1κ],else, where κ is an adiabatic exponent of the fuel and (pLpB)critical a predetermined pressure ratio. In particular, the predetermined pressure ratio is determined using the equation (pLpB)critical=(2κ+1)κκ−1 certainly.

[0025] In a configuration where hydrogen is used as fuel, κ = 1.4. Thus, the outflow function according to equations (7) and (8) simplifies to the following equation. ψ(pL,pB)={2536⋅3572≈0.4842, (pLpB)<(56)72≈0.52833.5⋅[(pLpB)107−(pLpB)127],otherwise

[0026] According to a further development of the invention, the adjusted correction variable is additionally determined using the fuel valve model based on the combustion air pressure and / or the fuel pressure. Additionally, the correction model is adjusted based on the combustion air pressure and / or the fuel pressure. Advantageously, a more differentiated determination of the adjusted correction variable is possible using the combustion air pressure and / or the fuel pressure. Furthermore, the correction model can be adjusted more comprehensively using the combustion air pressure and / or the fuel pressure.

[0027] In particular, the second fuel valve function B2(...) of the fuel valve model B is used to determine the adjusted correction value k a additionally dependent on the combustion air pressure p Land the fuel pressure p B , in particular ka=B2(mist,tBD,pL,pB) In particular, the first fuel valve function B1(...) and the second fuel valve function B2(...) are chosen such that equations (6) and (10), in particular for m soll = m ist and k = k a , are transformable into one another - in particular equivalent.

[0028] In particular, the actual fuel mass m ist and the corresponding adjusted correction value k a an additional data point (mist,k=ka=B2(mist,tBD,pL,pB),pL,pB) for the correction model K M , where the correction model K M adjusted based on the additional data point.

[0029] According to a further development of the invention, it is provided that the fuel valve energization duration is additionally determined by means of the fuel valve model 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.

[0030] In the context of the present technical teaching, the flow coefficient c d A dimensionless number with a value from 0 to 1 that indicates how unhindered the fuel can flow in the internal combustion engine - especially the fuel valve. In particular, the flow coefficient c dinfluenced by the geometry of the fuel valve. Under otherwise identical conditions, the greater the flow coefficient, the more fuel per unit of time—in particular, a larger mass flow—flows through the fuel valve. Alternatively or additionally, a first mass flow of fuel in the fuel valve with a first flow coefficient is greater than a second mass flow of fuel in the fuel valve with a second flow coefficient if—under otherwise identical conditions—the first flow coefficient is greater than the second flow coefficient.

[0031] In the context of the present technical teaching, the opening area A is a cross-sectional area of the fuel valve at the point where the fuel exits the fuel valve and is introduced 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 changes in the first introduction interval [0,t o ] increased - especially from 0 m 2 to a maximum opening area A o -, where the opening area A in the second insertion interval [t o ,t BD ] remains constant - in particular the maximum opening area A o - and wherein the opening area A in the third insertion interval [t BD ,t BD + t c ] reduced - especially from the maximum opening area A o to 0 m 2 .

[0032] In the context of the present technical teaching, the fuel temperature T B an absolute temperature of the fuel - measured in Kelvin - inside the fuel valve.

[0033] In the context of the present technical teaching, the specific gas constant R B using the equation RB=R1MB calculated, where R I the ideal gas constant - in particular RI=8.3145 Jmol K− and with M B an average molar mass of the fuel. In the embodiment where hydrogen is used as fuel, MB=2.01588gmol for molecular hydrogen H2. Thus, the specific gas constant R B for hydrogen according to equation (12) RB=4.1245Jg K

[0034] In particular, the first fuel valve function B1(...) of the fuel valve model B is used to determine the fuel valve energization duration t BD additionally dependent on the flow coefficient c d , the opening area A, the fuel valve opening time t o , the fuel valve closing time t c , the fuel temperature T B and the specific gas constant R B , in particular tBD=B1(msoll,k,pL,pB,cd,A,to,tc,TB,RB) applies.

[0035] 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 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.

[0036] In particular, the second fuel valve function B2(...) of the fuel valve model B is used to determine the adjusted correction value k a additionally dependent on the flow coefficient c d , the opening area A, the fuel valve opening time t o , the fuel valve closing time t c , the fuel temperature T B and the specific gas constant R B , in particular ka=B2(mist,tBD,pL,pB,cd,A,to,tc,TB,RB) In particular, the first fuel valve function B1(...) and the second fuel valve function B2(...) are chosen such that equations (13) and (14), in particular for m soll = m ist and k = k a , are transformable into one another - in particular equivalent.

[0037] According to a further development of the invention, a Gaussian process model is used as the correction model. Gaussian process models are particularly suitable for developing a correction model: Compared to polynomial-based models, they are particularly easier to adapt to new or changed data points in the application field, and they exhibit more suitable and physically more correct behavior in the boundary regions of the given parameter space. Compared to physical models, they require significantly less computational effort. Furthermore, they enable the direct use of test bench data. Such a Gaussian process model is particularly based on stored data points (X) obtained, for example, in test bench tests and / or during real operation of the internal combustion engine. b , Y b ) and / or refined, where X b ∈ ℝ i×jin particular i input variables for j different operating states and with Y b ∈ ℝ j×n in particular, n output variables are specified for the j different operating states. In one embodiment, in a first step, j=1, where j is incremented by 1 in each iteration step of the measurement of the internal combustion engine. In an alternative embodiment, a basic grid of the Gaussian process model, in particular j operating states, is known, and based on new additional operating states - in particular new input variables and associated output variables - the basic grid of the Gaussian process model is refined and / or adapted, where j is incremented by 1 in each iteration step of the measurement of the internal combustion engine. In particular, the input variables X b a subset of the union of the target fuel mass m soll , the combustion air pressure p L and the fuel pressure p B, so that in particular i≤3, particularly preferably i=3, holds. The output variable Y b is the correction quantity k, so that in particular n=1. Furthermore, the Gaussian process model is characterized by a given 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 included in the original data set for o different operating states X u ∈ ℝ i × o given: E(Xu)=m(Xu)+K(Xu,Xb)(K(Xb,Xb))−1(Yb−m(Xb)), Var(Xu)=K(Xu,Xu)−K(Xu,Xb)(K(Xb,Xb))−1K(Xb,Xu), with a mean function m(X u ) and a covariance function K, which depends on the Euclidean distance r between two points x r , x s depends on: K(Xr,Xs)=(k(X1:i,pr,X1:i,qs))p=1,....,q=1,....,j, k(xr,xs)=σF2exp(−r(xr,xs)22l2)+δr,sσN2, 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 for two different points x r , x s and δ r,s = 1 for two identical points x r , x s , which advantageously makes a numerical calculation of the function K( · , · ) more stable, in particular a numerical calculation of an inverse more stable. Furthermore, in particular r(xr,xs)2=‖xr−xs‖22 where || · ||2 denotes 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 ) ∈ ℝ j×j , K(X u ,X u ) ∈ ℝ o×o and K(X b ,X u ) ∈ ℝi×o .

[0038] For the mean function m(X u ) is preferably m(X u )=1.

[0039] In one embodiment, the correction value k is then calculated from equations (5) and (15) using the equation k=KM(msoll,pL,pB)=E(Xu=(msolllpLpB)) certainly.

[0040] According to a further development of the invention, a nozzle equation is used as the fuel valve model. This advantageously allows for a more precise modeling of the fuel valve in a simple and rapid manner.

[0041] In particular, the nozzle equation describes a temporal change of a time-variable fuel mass m(t) using the equation m˙(t)=kA(t)cdψ(pL,pB)pB2RB TB with a time-varying opening area A(t). This means that for a fuel mass per injection interval [0,t BD + t c ] of the fuel valve m=k cdψ(pL,pB)pB2RB TB∫0tBD+tcA(t)dt=k cdψ(pL,pB)pB2RB TBA*(tBD+tc), where A * (t) denotes the antiderivative of the time-varying opening area A(t).

[0042] In particular, to determine the fuel valve energization time t BD for the fuel mass m = m soll and equation (22) is set to t BD changed. tBD=A*−1(msolk cdψ(pL,pB)pB2RB TB)−tc

[0043] Alternatively or additionally, to determine the adjusted correction value k a for the fuel mass m = m ist and for the correction quantity k = k a and equation (22) is solved for k a changed. ka=mistcdψ(pL,pB)pB2RB TBA*(tBD+tc)

[0044] In one embodiment, the time-varying opening area A(t) of the fuel valve is determined using the equation A(t)={Aotot, if t≤toAo, if to <t<tBD−Aotct+Ao(tBD+tc)tc, falls t≥tBD This means that the integral from equation (22) can be written as ∫0tBD+tcA(t)dt=∫0toAototdt+∫totBDAodt+∫tBDtBD+tc−Aotct+Ao(tBD+tc)tcdt=−12Aoto+Ao(tBD−to)+12Aotc where the value of the integral can also be used in equations (22) to (24). It is therefore valid for the determination of the fuel valve energization time t BD using equations (23) and (26) tBD=msollAo k cdψ(pL,pB)pB2RB TB+to2−tc2 and for the determination of the adjusted correction value k a using equations (24) and (26) ka=mistcdψ(pL,pB)pB2RBTB[−12Aoto+AotBD+12Aotc].

[0045] Particularly preferably, the method is carried out cyclically, in particular at a frequency of 0.01 Hz to 1 Hz. Alternatively or additionally, the method is carried out at a predetermined time interval in operating hours. Alternatively or additionally, the method is carried out in an event-driven manner.

[0046] The object is also achieved by providing a control device configured to carry out a method according to the invention or a method according to one or more of the previously described embodiments. 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 unit of an internal combustion engine. In connection with the control device, the advantages already explained in connection with the method arise in particular.

[0047] The control device is particularly configured to be connected to the fuel valve and configured to control 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.

[0048] The object is also achieved by providing a fuel valve device with a fuel valve and a control device according to the invention or a control device according to one or more of the previously described embodiments. In connection with the fuel valve device, the advantages already explained in connection with the method and the control device arise in particular.

[0049] 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.

[0050] In particular, the fuel valve device additionally comprises the combustion air pressure sensor. Alternatively or additionally, the fuel valve device comprises the fuel pressure sensor. Alternatively or additionally, the fuel valve device comprises the fuel mass sensor.

[0051] The control device is, in particular, operatively connected to the fuel valve and configured to control 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.

[0052] Finally, the object is also achieved by providing an internal combustion engine with at least one combustion chamber, an intake 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 previously described embodiments. A fuel valve of the fuel valve device is arranged fluidically upstream of an intake valve along a combustion air flow direction, in particular a charge air flow direction. In connection with the internal combustion engine, the advantages that have already been explained in connection with the method, the control device, and the fuel valve device arise in particular.

[0053] The invention is explained in more detail below with reference to the drawings, which show: Fig. 1 a schematic representation of an embodiment of an internal combustion engine, and Fig. 2 a flowchart of an embodiment of a method for operating a fuel valve of the internal combustion engine.

[0054] Fig. 1 shows a schematic representation of an 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 configured to control it. Furthermore, the combustion chamber 5 has an inlet valve 11.1 and an outlet valve 11.2. The fuel valve device 3 is arranged fluidically upstream of the inlet valve 11.1 along a combustion air flow direction 13, in particular a charge air flow direction 13. Furthermore, an exhaust gas flow direction 14 is shown.

[0055] Particularly preferably, the fuel valve device 3 additionally has a combustion air pressure sensor 15, in particular a boost pressure sensor 15, and / or a fuel pressure sensor 17. The combustion air pressure sensor 15 is configured to measure a combustion air pressure p L , in particular a boost 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.

[0056] The control device 9 is in particular designed 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.

[0057] Fig. 2 shows a flowchart of an embodiment of a method for operating the fuel valve 7 of the internal combustion engine 1 according to Fig. 1.

[0058] 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.

[0059] For clarity, the flow arrows for steps S1 to S4 are shown as solid arrows. In contrast, the flow arrows for steps S6 and S7 are shown as dashed arrows. Intermediate arrows have also been added to make the flow directions easier to identify.

[0060] In a first step S1, a target fuel mass m soll for delivery through the fuel valve.

[0061] In a second step S2, a correction model K M based on the target fuel mass m soll a correction value k is determined. In one embodiment, the correction value k is determined using equation (1). In particular, in the second step S2, the combustion air pressure p L taken into account in order to use the correction model K M to determine the correction quantity k. In a particularly preferred embodiment, equation (5) is used to determine the correction quantity k.

[0062] In particular, the correction model K M based on at least one data point (m ist , k). Preferably, the fuel pressure p B taken into account in order to use the correction model K Mto determine the correction quantity k. The correction model K is particularly preferred. M based on at least one data point (m ist , k, p L , p B ). The correction model K is particularly preferred. M a Gaussian process model is used - in particular according to equations (15) to (19). In one embodiment, the correction value k is then determined based on equations (5) and (15) using equation (20).

[0063] In a third step S3, a fuel valve model B is used to determine the target fuel mass m soll and the correction value k a fuel valve energization time t BD In particular, the fuel valve energization time t BD determined using equation (2).

[0064] In particular, in the third step S3, the combustion air pressure p Ltaken into account in order to determine the fuel valve energization time t using the fuel valve model B BD Alternatively or additionally, the fuel pressure p B taken into account in order to determine the fuel valve energization time t using the fuel valve model B BD In particular, the fuel valve energization time t BD determined using equation (6). Preferably, the combustion air pressure p L and the fuel pressure p B via an outflow function ψ(p L , p B ) according to equation (7) - in particular equations (8) and (9) for hydrogen as fuel - into the fuel valve model B according to equation (6).

[0065] In particular, in the third step S3, at least one parameter 21 is additionally 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, are taken into account in order to determine the fuel valve energization time t by means of the fuel valve model B BD In particular, the fuel valve energization time t BD determined using equation (13).

[0066] In a fourth step S4, the fuel valve 7 is energized with the fuel valve energization duration t BD In particular, the fuel valve 7 is controlled with the fuel valve energization duration t BD controlled to achieve one of the target fuel mass m sollcorresponding actual fuel mass. In particular, the fuel valve 7 is energized during a current supply - in particular the fuel valve current supply period t BD - opened and / or remains open. The fuel valve 7 is opened for the fuel valve opening time t o opened. In addition, the fuel valve 7 is opened for the fuel valve closing time t c closed. This will cause the fuel valve 7 to close in a first injection interval [0,t o ] opened, in a second insertion interval [t o ,t BD ] the fuel valve 7 is opened and in a third injection interval [t BD ,t BD + t c ] the fuel valve 7 is closed.

[0067] In an optional fifth step S5, the fuel valve 7 is actuated with the fuel valve energization duration t BD actual fuel mass delivered m istIn particular, the actual fuel mass m ist determined directly or indirectly by means of the fuel mass sensor 19.

[0068] In an optional sixth step S6, the fuel valve model B is used to calculate the actual fuel mass m ist and the fuel valve energization time t BD an adjusted correction value k a In particular, the adjusted correction value k a determined using equation (3).

[0069] In particular, in the sixth step S6, the combustion air pressure p L taken into account in order to calculate the adjusted correction value k using the fuel valve model B a Alternatively or additionally, the fuel pressure p B taken into account in order to calculate the adjusted correction value k using the fuel valve model B a In particular, the adjusted correction value k adetermined using equation (10).

[0070] In particular, in the sixth step S6, the at least one parameter 21 is additionally selected from a group consisting of the flow coefficient c d , the opening area A, the fuel valve opening time t o , the fuel valve closing time 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, are taken into account in order to determine the adjusted correction value k by means of the fuel valve model B a In particular, the adjusted correction value k a determined using equation (14).

[0071] Particularly preferably, in the third step S3 and / or the sixth step S6, 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 for a time-varying opening area A(t) of the fuel valve according to equation (25) and the fuel valve energization duration t BD is calculated using equation (27) and the adjusted correction value k a determined using equation (28).

[0072] In an optional seventh step S7, the adjusted correction value k a and the actual fuel mass m ist the correction model K M In particular, the actual fuel mass m ist and the corresponding adjusted correction value k a an additional data point according to equation (4) for the correction model K M , where the correction model K Madjusted based on the additional data point.

[0073] In particular, in the seventh step S7, the correction model K M additionally based on the combustion air pressure p L Alternatively or additionally, the correction model K M additionally based on the fuel pressure p B In particular, the actual fuel mass m ist , the corresponding adjusted correction value k a , the corresponding combustion air pressure p L and the corresponding fuel pressure p B an additional data point according to equation (11) for the correction model K M , where the correction model K M adjusted based on the additional data point.

[0074] In an optional eighth step S8, the combustion air pressure p L In particular, the combustion air pressure p Ldetermined directly or indirectly by means of the combustion air pressure sensor 15.

[0075] In an optional ninth step S9, the fuel pressure p B In particular, the fuel pressure p B determined directly or indirectly by means of the fuel pressure sensor 17.

Claims

[1] Method for operating a fuel valve (7) of an internal combustion engine (1), wherein - a target fuel mass (m soll ) is specified for delivery through the fuel valve (7), whereby - using a correction model (K M ) based on the target fuel mass (m soll ) a correction value (k) is determined, where - by means of a fuel valve model (B) based on the target fuel mass (m soll ) and the correction value (k) a fuel valve energization time (t BD ), where - the fuel valve (7) with the fuel valve energization duration (t BD ) is controlled. [2] The method according to claim 1, wherein - a fuel valve (7) actuated with the fuel valve energization duration (t BD ) actual fuel mass actually delivered (m ist ), where - using the fuel valve model (B) based on the actual fuel mass (m ist ) and the fuel valve energization time (t BD ) an adjusted correction value (k a ), where - based on the adjusted correction value (k a ) and the actual fuel mass (m ist ) the correction model (K M ) is adjusted. [3] Method according to one of the preceding claims, wherein - using the correction model (K M ) the correction value (k) is additionally dependent on a combustion air pressure (p L ) and / or a fuel pressure (p B ), where - using the fuel valve model (B) the fuel valve energization time (t BD ) additionally based on the combustion air pressure (p L ) and / or the fuel pressure (p B ) is determined. [4] Method according to claims 2 and 3, wherein - using the fuel valve model (B) the adjusted correction value (k a ) additionally based on the combustion air pressure (p L ) and / or the fuel pressure (p B ), where - the correction model (K M ) additionally based on the combustion air pressure (p L ) and / or the fuel pressure (p B ) is adjusted. [5] Method according to one of the preceding claims, wherein the fuel valve energization duration (t BD ) additionally based on 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 time (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). [6] Method according to one of the preceding claims, wherein the adjusted correction value (k a ) additionally based on at least one parameter (21) selected from a group consisting of the flow coefficient (c d ), the opening area (A), the fuel valve opening time (t o ), the fuel valve closing time (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). [7] Method according to one of the preceding claims, wherein the correction model (K M ) a Gaussian process model is used. [8] Method according to one of the preceding claims, wherein a nozzle equation is used as the fuel valve model (B). [9] Control device (9) for carrying out a method according to one of the preceding claims. [10] Fuel valve device (3) with a fuel valve (7) and a control device (9) according to claim 9. [11] Internal combustion engine (1) with 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 fluidically upstream of an inlet valve (11.1) along a combustion air flow direction (13).

Images