KR20190022361A - Method for the adaptation of an opening delay and a closing delay of a metering valve - Google Patents

Abstract

The present invention relates to a method for adjusting an opening delay (delayA) and a closing delay (delayB) of a metering valve, wherein deviations between prediction delay and measurement delay are used for matching actuation durations (act) later. The opening delay (delayA) and the closing delay (delayB) are adjusted independently. The prediction delay (delayA_pre) is calculated from an opening delay according to ambient environment (delayA_amb) and an opening delay factor (delayA_factor).

Description

BACKGROUND OF THE INVENTION 1. Field of the Invention [0001] The present invention relates to a method for adapting an opening delay and a closing delay of a metering supply valve,

The present invention relates to a method for adaptation of open delay and closing delay of metering feed valves using matching of operating hours in the future. The present invention also relates to a computer program for executing each step of the method when executed in a computer, and a machine-readable storage medium storing the computer program. Finally, the present invention relates to an electronic control device configured to execute the method.

In particular in the automobile in the exhaust gas line of an internal combustion engine, SCR (S elective C atalytic R eduction) the internal combustion engine with a catalytic converter is disposed for reducing the nitrogen oxide (NOx) contained in exhaust gas of an internal combustion engine in the presence of a reducing agent with nitrogen Are known in the art. As a result, the proportion of nitrogen oxides in the exhaust gas can be greatly reduced. Ammonia (NH ₃₎ is required for execution of the reaction. As the reducing agent, NH ₃ separation reagents added to and mixed with the exhaust gas are used. To this end, in general, the number of elements injected into the exhaust gas line upstream of the SCR catalytic converter is used.

The reducing agent solution is usually held in a reducing agent tank in an automobile. A hydraulic metering system is generally provided for transporting and metering the urea water, including a feed pump, a pressure line, a metering supply module with one or more metering feed valves, and a required sensor device and an electronic control device. The transfer pump transfers urea water from the reductant tank into the metering supply module via the pressure line. To meet the needs of metering, the required or desired metering feed of the reducing agent solution is metered into the exhaust line through the metering feed valve (s).

The metering feed valve is configured as a solenoid valve with a solenoid and a movable solenoid armature connected to the valve needle. In the current unfilled state, the valve spring keeps the valve needle closed via the spring force. When current is applied to the solenoid, a magnetic force acts on the solenoid armature so that the solenoid armature is pulled toward the solenoid against the spring force of the valve spring, thereby causing the valve needle to open the metering supply valve. At the Begin of Injection Period (BIP), the valve is fully opened. If the current no longer flows through the solenoid, the metering feed valve is closed again and the metering input ends at the End of Injection Period (EIP). As a result, the metering feed amount of the reducing agent solution is adjusted through the metering feed period in which the metering feed valve is open and the reducing agent flow.

However, it is important to note that the operating period during which the solenoid is energized is different from the metering period. After the supply of current to the metering feed valve, an open delay occurs in which the magnetic force necessary for opening is formed before the valve needle opens the metering feed valve. In the same way, a closing delay occurs when the metering feed valve is closed again when it is open, because the magnetic field must be extinguished again. In addition, DE 10 2008 000 695 A1 describes another effect which is to conclusively increase the closure delay. Wear-flattened surfaces can form on the stop for the solenoid armature and on these surfaces a lubrication gap flow can occur which causes the solenoid armature to become stuck on the stop when closing the metering feed valve. This effect is also referred to as hydraulic sticking.

In order to precisely adjust the metering supply, it is necessary to monitor the operating period and the metering period. DE 10 2014 200 346 A1 discloses a method and apparatus for correcting a metering feed valve. Here, at the end of the metering supply process, an erase voltage is supplied to the solenoid which is stepwise varied, and the time behavior of the current passing through the solenoid is recorded. The EIP is then determined within a predetermined time frame therefrom. Further, the closing delay is determined through the evaluation, and the operation period is finally corrected.

The present invention relates in particular to a method for adaptation of open delay and closing delay of a metering feed valve used for metering input of a reducing agent solution into an exhaust line together with a metering feed module as part of an SCR system. The metering feed valve is usually formed as a solenoid valve; A solenoid, and a solenoid armature connected to the valve needle. When current is applied to the solenoid, the solenoid armature rises against the spring force exerted through the valve spring, thereby opening the valve needle. At this time, the above-described open delay occurs. If no more current is supplied to the solenoid, the spring force predominates, resulting in the metering feed valve closing and closure delay occurring. In the present method, a predicted delay and a measured delay are determined for the open delay and the closed delay, respectively, and then compared with each other. Deviations that occur in some cases form the basis for future operating period matching.

Preferably, the matching of future operating periods is performed not only based on deviations of the preceding metering inputs but also taking into account previous adaptations. More preferably, a long-term adaptation function is used for adaptation of the opening delay and closing delay of the metering feed valve, in which the above-described deviations are incorporated. Accordingly, age-related changes and sample-variance related deviations, especially of the open delay and the closing delay, can be compensated.

The open delay is mainly due to the fact that the magnetic field of the solenoid armature is formed instantly, rather than being formed immediately, when current is supplied to the solenoid armature. The metering feed valve is opened only when the magnetic force exceeds the force resulting from the spring force of the valve spring and the pressure difference in the metering feed valve. Correspondingly, the spring force of the valve spring and the inductance and resistance of the solenoid act as an influence on the open delay. Conversely, closure delay has multiple sources. On the other hand, the magnetic force dissipates over time similar to the open delay, whereby the metering feed valve is closed only when the magnetic force again falls below the spring force. On the other hand, pressure and temperature-dependent hydraulic anchoring, which keeps the solenoid armatures open during the closing process, occurs. The effect of hydraulic pressure appears to be clearly predominant in the delayed closing of the obsolete valves. In other words, since the open delay and the closed delay are caused by different phenomena, it is preferable that the two delays are adapted through mutually different adaptation functions independently of each other.

For independent adaptation of the open delay, the predicted opening delay can be calculated from at least the open delay and the open delay depending on the surrounding environment. Preferably, the open delay according to the ambient environment can be read in the appropriate chart or can be calculated through a function of the pressure difference between the inlet side and the outlet side of the valve needle and the voltage and resistance of the solenoid of the metering feed valve. The open delay coefficient represents the characteristics of each metering feed valve acting on the open delay, and these characteristics are substantially the tolerances in the spring force of the valve spring and in the resistance of the solenoid. As a starting point, the opening delay due to the surrounding environment, which represents the "nominal state" of the valve spring, is considered. The open count can now be determined from the open delay of the preceding operation and the open delay due to the surrounding environment, where a quotient is preferably calculated. In this case, the open coefficient represents the deviation of the spring force from the "nominal state ". The spring force of the valve spring can be regarded as constant over a plurality of metering dosing cycles (even when not constant over the entire useful life of the metering feed valve), so that the open delaying coefficient can be assumed to be constant over time have. As a result, the open delay coefficient is multiplied by a function of the open delay according to the surrounding environment to obtain the predicted open delay. Optionally, filtering can be provided when determining the open delay.

For independent adaptation of the closure delay, the predicted closure delay can be calculated from at least the nominal closure delay and the additional closure delay, the additional closure delay is used as the offset to the closure delay, and the nominal closure delay Is added. As a result, deviations due to aging of the metering feed valve are learned. Preferably, the additional closure delay passes through the filtering before being added to the nominal closure delay. In filtering, individual measurement errors can be eliminated and related changes such as, for example, the exchange of components of a metering feed valve can be matched step by step.

According to one aspect, the nominal closure delay is determined by the spring strength of the valve spring; And the time characteristic curve of the magnetic force of the solenoid which can be expressed through the inductance, resistance and voltage of the solenoid; and the energy level at which the solenoid 20 is shut down.

According to another aspect, the nominal closure delay can be stored as a fixed nominal value for the SCR system, e.g., in an electronic control device, or in a machine-readable storage medium. The fixed nominal value for the nominal closing delay can thus be determined before the metering feed valve is used, for example already in production. As a result, the calculation of the nominal closing delay can be omitted during the operation of the metering feed valve.

Preferably, the filtered additional closure delay at the time of filtering is reset when the measured closing delay is different from the predicted closure delay more frequently than the determined threshold (which is likewise dependent on the filtered additional closure delay) . At this time, it is also considered that the measurement closure delay is continuously different from the predicted closure delay. As a result, it can automatically react quickly to component replacement.

The computer program of the present disclosure is configured to execute each step of the method when executed in a computer or a control device. The computer program of the present invention enables the implementation of the present method without making structural changes in conventional electronic control devices. To this end, the computer program of the present invention is stored in a machine-readable storage medium.

 The electronic control device according to the present invention configured to adapt the open delay and the closing delay is secured by installing the computer program of the present invention in a conventional electronic control device.

Embodiments of the present invention are illustrated in the drawings and described in further detail below.

1 shows a metering feed valve in which its open delay and closing delay are adapted by an embodiment of the method according to the invention;
Fig. 2 is a graph showing the position and operation of the valve needle of the metering feed valve of Fig. 1 and the measured current during the metering feed process over time in an embodiment of the method according to the invention.
Figure 3a is a diagram illustrating a first portion of a flow diagram in which an open delay is adapted by an embodiment of the method according to the present invention.
3B is a diagram showing a second part of the flow chart in which the closure delay is adapted by an embodiment of the method according to the invention.
3C is a diagram illustrating a third portion of the first portion of FIG. 3A and the second portion of FIG. 3B in a flow chart of one embodiment of the method according to the present invention.

1 shows a metering feed valve 10 as part of an SCR system, not shown in more detail, for metering dosing of a reducing agent solution into an exhaust gas line not shown. The metering supply valve 10 is formed as a solenoid valve and includes a solenoid 20; And a solenoid armature (21) connected to the valve needle (30). The metering feed valve 10 is also surrounded by a housing 50 that includes an inlet opening 51, a discharge opening 52 and a pressure chamber 53. In Figure 1 a closed metering feed valve 10 is shown in which the valve spring 40 uses a spring force F_s to bring the valve needle 30 into close contact with the discharge opening 52, The opening is closed.

When a current is supplied to the solenoid 20, a magnetic force F_m is formed and this magnetic force is applied to the solenoid armature 21 and the valve needle 30 connected to the solenoid armature against the spring force F_s of the valve spring 40, . When the magnetic force F_m of the solenoid 20 overcomes the spring force F_s of the valve spring 40, the valve needle 30 is pulled away from the discharge opening 52 in the direction of the solenoid 20, As a result, the metering feed valve 10 is opened and the reducing agent solution can be perfused through the discharge opening 52. When the metering feed valve is open, the flow of the reducing agent solution is shown through arrows 61 and 62. The reducing agent solution flows into the pressure chamber 53 of the metering supply valve 10 from the pressure line (not shown in both the transfer module and the pressure line) connected to the transfer module along the arrow 61 through the inlet opening 51. When the metering feed valve 10 is opened, the reducing agent flows through the discharge opening 52 along the arrow 62, is discharged from the pressure chamber 53, and is metered into the exhaust gas line.

In order to close the open metering feed valve 10 again, the current to the solenoid 20 is cut off, whereby the magnetic force F_m is extinguished. Thereby, when the magnetic force F_m is smaller than the spring force F_s, the valve needle 30 again comes close to the discharge opening 52 and closes the discharge opening. The opening and closing of the metering supply valve 10 is controlled by an electronic control device 70 connected to at least the solenoid 20 and controlling the current supply of the solenoid. In addition, the current flowing through the solenoid 20 and / or the voltage applied to the solenoid 20 can be measured.

Figure 2 shows the needle position 100 and act 110 of the metering feed valve of Figure 1 and the measured current 120 during the metering process over time t for one embodiment of the method according to the present invention. The graph shown is shown. The graph is divided into different regions, which are discussed in more detail below. If a metering feed request is present, actuation 110 via controller 70 is performed by supplying current to solenoid 20 as described above. As a result, the valve needle position 100 is changed from the closed position to the open position. However, this is not done immediately, as can be seen from the graph, but over a period of time referred to as an open delay (delay A). In other words, the opening delay (delayA) is a period of time elapsing from the operation 110 for opening the metering supply valve 10 to the maximum opening position (injection period start point (BIP)) of the valve needle 30 .

If weighing is to end, act 110 is set to zero and solenoid 20 is no longer supplied with current accordingly. Again, the valve needle position 100 does not change immediately from the open position to the closed position, but rather over a period of time referred to as a closing delay (delay B). In other words, the closing delay (delay B) elapses from the end of the act 110 for closing the metering feed valve 10 until it reaches the closed position of the valve needle 30 and at the end of the injection period EIP It indicates the period of ending the weighing input. The time during which the reducing agent solution is metered in between the injection period starting point (BIP) and the injection period ending point (EIP) is referred to as the absolute metering supply period (inj_total) and is also shown in FIG. In the graph of Fig. 2, it can be seen that in this embodiment the open delay delayA is shorter than the closure delay delayB. The reasons why the open delay (delayA) and the closure delay (delayB) are different are in the phenomena described in detail below. Depending on the metering feed valve 10 and operation 110, the open delay delayA may also be longer than the closure delay (delayB), and both delays may be the same length.

2, the measured current 120 for the solenoid 20 is shown. The measured current 120 provides the possibility to infer the injection period start point (BIP) and the injection period end point (EIP). Likewise, the measured voltage applied to the solenoid 20 can be used for determination of the injection period start point (BIP) and the injection period end point (EIP). In the characteristic curve of the measured current 120, the local minimum value 121 is identified at the injection period start point (BIP) because the induction that acts in the opposite direction as the needle is stopped and no longer moves It ends. At the injection period end point (EIP), the local maximum value 122 caused by the termination of the mutual induction, i. E. The measured current 120 is reproduced as a function of time t, and then a simple evaluation is achieved by deriving the function. If the injection period start point (BIP) and the injection period end point (EIP) are known, on the other hand, the absolute metering supply period (inj_total) is calculated from these time differences. On the other hand, as described above, the open delay delayA is calculated as the period between the starting point of the operation 110 and the injection period starting point (BIP), where the measured current 120 has a local minimum value 121. [ Similarly, the closing delay (delay B) is calculated as the period between the end of the act 110 and the end of the injection period (EIP), where the measured current 120 has a local maximum value 122. In these calculated information, by comparison with the required parameters, deviations in the metering feed are detected and balanced. However, in the above method, only the metering feed that has already been performed can be analyzed. Operation 110 of metering feed valve 10 is performed over actuation period act.

 3a, 3b and 3c, a flow diagram of an embodiment of the method according to the invention is shown, in which the adaptation of the open delay (delayA) in Fig. 3a and the adaptation of the closure delay (deltaB) in Fig. And are integrated to match the future act act in Fig. 3c.

In FIG. 3A, in the first step 200, the measured current 120 is recorded. Further, the pressure difference? P between the inlet side and the outlet side of the valve needle 30, the inductance L_coil and the resistance R_coil at the solenoid 20 of the metering supply valve 10 (DelayA_amb) is calculated 201 (step 201). In yet another embodiment, the open delay (delayA_amb) according to the environment for the specified variables is read in the diagram.

The open delay delayA mainly occurs when the solenoid 20 generates a magnetic force F_m over a certain period of time during the actuation 110 of the solenoid 20 and the magnetic force F_m is generated when the valve needle position 100 is opened (F_s) of the valve spring 40 and the pressure difference in the metering feed valve, so as to move in the direction of the position of the metering feed valve. Now, an opening delay (delayA_amb) according to the surrounding environment is determined by a pressure difference [Delta] p at the time of formation of the magnetic force F_m; And the continuously varying influence of the inductance (L_coil) and the resistance (R_coil) of the solenoid (20).

Further, the open delay coefficient (delayA_factor), which substantially represents the deviations of the spring force F_s and / or the tolerances in the resistance R_coil of the solenoid 20, (delay A) and the open delay due to the surrounding environment (delay A_amb) (202).

On the basis of this, the delay delay factor delayA_factor is constant for different metering feed valves 10, while it is variable for different metering feed valves 10 or valve springs 40 over time t. do. The open delay factor (delayA_factor) is usually varied only when the metering feed valve 10 or portions of the metering feed valve are degraded or replaced with respect to their function. In order to determine the predicted open delay delayA_pre, an open delay delayA_amb and an open delay factor delayA_factor according to the surrounding environment are multiplied together according to the following equation (203).

In a further step, metering feed 204 of the reducing agent solution into the exhaust line is performed. In this case, as described in connection with FIG. 2, the measurement opening delay (delayA_meas) is determined 205 in the characteristic curve of the measured current 120. Subsequently, the validity check 206 of the measurement open delay (delayA_meas) using the predicted open delay (delayA_pre) is performed. If the measurement open delay delayA_meas matches the predicted open delay delayA_pre, that is, if the difference is less than the first threshold S ₁ , then the measurement open delay delayA_meas is stored 207 as the open delay delayA, , Then used in the next procedure. However, if the difference between the measurement open delay (delayA_meas) and the theoretical open delay (delayA_pre) exceeds the first threshold value S ₁ , the open delay delayA is reset to the predicted open delay delayA_pre (208). As a result, a recovery point is provided in the case of a measured open delay (delayA_meas), or in the presence of other errors. The newly determined open delay (delayA) is used for the determination 202 of the open delay factor (delayA_factor) in the subsequent metering feed process. When the open delay (delayA) is reset (208) to the predicted open delay (delayA_pre), the delayA-factor is determined to be 1 (202), which is proved from the combination of Equations 1 and 2. [

In FIG. 3B, the current 120 measured in the first step 300 is also recorded. In this case, if the characteristic curve of the measured current 120 has been recorded over the appropriate time period t, the measurements performed in step 200 of FIG. 3A may be used. Following this, the raw value of the measurement closure delay (delayB_meas_raw) from the measured current 120 is determined (301).

The closing delay B depends on whether the magnetic force F_m is extinguished over a certain period of time after the actuation 110 of the solenoid 20 is shut off in the same manner as the opening delay delayA, The spring force F_s of the valve spring 40 must exceed the magnetic force F_m so that the position 100 is moved in the direction of the closed position. Of course, this effect is negligible compared to hydraulic securing in the case of severely aged metering feed valves 10. The spring force F_s of the valve spring 40, the inductance L_coil of the solenoid, the resistance R_coil and the voltage U_coil as the characteristic values for each metering supply valve 10 and the solenoid 20, From the energy level [epsilon], the nominal closure delay (delayB_def) is calculated 302. In another embodiment, the nominal closing delay (delayB_def) may be determined and stored in the electronic control unit 70 as a fixed nominal value before the metering feed valve 10 has already been used, e.g. during manufacturing.

In addition to the nominal closure delay (delayB_def), an additional closure delay (delayB_add) is provided which takes into account the tolerances during manufacture of the metering supply valve 10 and the aging-related deviations. The additional closure delay (delayB_add) is determined (303) as the deviation of the raw value (delayB_meas_raw) of the measurement closure delay for the nominal closure delay (delayB_def). Subsequently, to obtain the filtered additional closure delay (delayA_add_fil), a long time filtering 304 of the additional closure delay (delayA_add) is performed. This filtering 304 is used for monitoring the long-term behavior of the metering feed valve 10, so that the filtering 304 eliminates individual measurement errors on the one hand and, on the other hand, Performs step-by-step matching on new values when the components of metering feed valve 10 such as spring 40 or metering feed valve 10 itself are replaced. For filtering 304, a digital low-pass filter is suitable. The filtered additional closure delay (delayB_add_fil) is added (305) to the nominal closure delay (delayB_def) according to the following equation 3 to determine the predicted closure delay (delayB_pre).

In a further step, a metering feed 306 of the reducing agent solution into the exhaust line is performed, which may correspond to the metering feed 204 of FIG. 2 in relation to the opening delay. The measurement closure delay (delay B_meas) for the current metering feed process is determined 307 in the characteristic curve of the measured current 120. Following this, a plausibility check 308 of the measurement closure delay (delayB_meas) using the predictive closure delay (delayB_pre) is performed. If the measurement closure delay (delay B_meas) coincides with the predicted closure delay (delay B_pre), that is to say if their difference is below the second threshold S ₂ , the measurement closure delay (delay B_meas) is stored as a closure delay (delay B) 309), and subsequently used to determine the metered feed amount (404). However, if the difference between the predictive close delay (delayB_pre) and the measured close delay (delayB_meas) exceeds the second threshold (S ₂ ), the error counter E is increased (310). If the error counter E falls below the third threshold S ₃ in the query step 311, the close delay (delay B) is reset to the predicted close delay (delay B_pre) (312). As a result, a recovery point is provided in the case of a misclosed delay (delayB_meas) or in the presence of other errors. However, if the error counter E exceeds the third threshold S ₃ , then the filtered further closing delay (delayB_add_fil) is reset (313) so that, for example, the component of the metering feed valve 10 The artifact artefact that interferes with the decision 305 of the predicted closing delay (delayB_pre) due to the defective or replacement of the metering feed valve 10 itself may be delayed after the number of error iterations determined by the third threshold value S3 Removed. Subsequently, similarly, the closure delay (delay B) is reset to the predicted closure delay (delay B_pre) (313). The determination 304 of the filtered measurement closure delay (delayB_meas_fil) and the determination 309 of the closure delay (delayB) are connected only through the reset 313 of the filtered additional closure delay (delayB_add_fil).

3c, the calculation 400 of the required metering supply period inj_des of the maximum mass flow rate dm_max of the reducing agent at the start time is determined in the following Equation 4, after the required metering supply amount m_des of the reducing agent for the current operating conditions is determined Therefore, it is performed.

(Act_des) from the required metering supply period (inj_des) is calculated (401) according to the following Formula 5, and the predicted opening delay (delayA_pre) in FIG. 3A is added to the required metering supply period inj_des The predictive closure delay (delayB_pre) at 3b is subtracted from the required metering supply period inj_des.

Now, a future operating period act for the next weighing input is determined based on the preceding operating period (402).

After operation 110 has been completed and an open delay 208 and a closing delay 208 determined from the measured current (or measured voltage) of solenoid 20 have been determined 207,309, The absolute dispensing period inj_total is calculated 403 using the open delay delayA determined in FIG. 3A and the closed delay determined in FIG. 3B according to Equation 6 below.

Finally, the actual metering supply amount m is calculated (404) by using the absolute metering supply period inj_total calculated in the step 403 instead of the required metering supply period inj_des in the equation 4. In yet another embodiment, alternatively, the determination of the integration of the metered amount of supply performed during metering may be corrected for the correct absolute metering feed duration inj_total just computed above.

Claims (14)

As a method for adapting the opening delay (delayA) and the closing delay (delayB) of the metering supply valve 10, the deviation between the prediction delay (delayA_pre, delayB_pre) and the measurement delay (delayA_meas, delayB_meas) A method of adaptation of an open delay and a closing delay of a metering feed valve, which is used for matching. The method of claim 1, wherein the deviations are included in a long-term adaptive function (delayA_factor, delayB_add_fil), and the long-term adaptive function delayA_factor, delayB_add_fil is used for adaptation of an open delay delayA and a delayB Of the metering feed valve. 3. Method according to claim 1 or 2, characterized in that the open delay (DelayA) and the closing delay (DelB) are adapted independently of each other. 4. A method according to any one of claims 1 to 3, characterized in that the predictive open delay (delayA_pre) is calculated (203) from at least an open delay (delayA_amb) and an open delay factor (delayA_factor) A method for adapting an open delay and a closing delay of a supply valve. 5. The method of claim 4, wherein the open delay (delayA_amb) according to the ambient environment is read in the diagram; (201) calculated through a function of a voltage (U_coil) and a resistance (R_coil) at the solenoid (20) of the metering supply valve (10) ; Wherein the opening and closing delay of the metering feed valve is adjusted. 6. The metering feed valve according to claim 4 or 5, characterized in that the open delay coefficient (delayA_factor) is determined (202) from an open delay (DeltaA) of the preceding operation and an open delay An adaptation method of open delay and closed delay. 7. The method of any one of claims 1 to 6, wherein the predictive closure delay (delayB_pre) comprises at least a nominal closure delay (delayB_def) and an additional closure delay (delayB_add, delayB_add_fil) used as an offset to the closure delay (delayA) (305). ≪ / RTI > A method as claimed in claim < RTI ID = 0.0 > 31, < / RTI > 8. The method of claim 7, wherein the nominal closure delay (delayB_def) is selected from the group consisting of a spring strength (F_s) of the valve spring (40); The inductance L_coil, the resistance R_coil, and the voltage U_coil of the solenoid 20; And an energy level (epsilon) at which said solenoid (20) is shut down (302). 8. A method according to claim 7, characterized in that the nominal closing delay (delayB_def) is stored as a fixed nominal value for each SCR system (1). 10. A method according to any one of claims 7 to 9, characterized in that the additional closing delay (delayB_add) passes through filtering (304). 11. The method of claim 10, wherein the filter (304) when, measured closed delay threshold (S ₃₎ more frequently predicted closure delay (delayB_pre), and if different, the filtered additional closing delay (delayB_add_fil) than (delayB_meas) is determined the (313) when the metering feed valve is closed. 12. A computer program configured to perform each of the steps of the method of any one of claims 1-11. 13. A machine-readable storage medium having stored thereon a computer program according to claim 12. An electronic control device (70) configured to perform an adaptation of an opening delay (delayA) and a closing delay (delayB) of a metering feed valve (10) using a method according to any one of the preceding claims.

Images