Method, control device, and computer program product for the on-board determination of pollutant emission masses of an internal combustion engine while condensate is being formed in the exhaust gas aftertreatment device

Abstract

The method according to the invention for the on-board determination of pollutant emission masses of an internal combustion engine (1) with an exhaust gas aftertreatment device (2) is carried out by executing program instructions of the computer program product (20) according to the invention by means of an electronic control device (7) paired with the internal combustion engine (1) and / or the exhaust gas aftertreatment device (2). In the process, sensor signal values (AS_Sig) provided by an exhaust gas sensor (6c) are continuously detected and the quantity of condensate stored in the exhaust gas aftertreatment device (2) is continuously determined. On the basis of the determined condensate quantity, sensor signal correction values (AS_Sig_Kw) for the sensor signal values (AS_Sig) which are representative of the continuous storage or release of the at least one pollutant by means of the stored condensate quantity are continuously determined using at least one other operating and / or system parameter. The pollutant emission masses are determined during the operation of the internal combustion engine (1) on the basis of corrected sensor signal values (AS_Sig_Korr) determined using the sensor signal correction values, allowing a more precise detection of the pollutant masses actually being emitted and thus a more precise monitoring of the conformity of the operation of the internal combustion engine (1) with existing pollutant emission laws.

Description

[0001] 202401196

[0002] 1

[0003] Description

[0004] Method, control device and computer program product for on-board determination of pollutant emission masses of an internal combustion engine during condensation in the exhaust aftertreatment device

[0005] The invention relates to a method for on-board determination of pollutant emission masses from an internal combustion engine (ICU) with an exhaust aftertreatment device, i.e., the pollutant emission masses that leave the exhaust aftertreatment device downstream of the ICU and are thus released into the environment. On-board determination in this case means that the pollutant emission masses are continuously determined during the intended operation of the ICU by means of an electronic measuring device assigned to the ICU and / or the exhaust aftertreatment device. This corresponds to so-called on-board monitoring (OBM) of pollutant emissions during operation.Such an electronic measuring device typically consists of an electronic control unit designed to operate the internal combustion engine and / or the exhaust aftertreatment system, and at least one exhaust gas sensor connected to the control unit. This sensor provides signal values ​​representative of the concentration of at least one pollutant in the exhaust gas stream exiting the internal combustion engine's aftertreatment system. The electronic control unit receives these sensor signals and, based on them, calculates the pollutant emission masses by executing corresponding stored program instructions in an electronic processing unit (processor).

[0006] The invention further relates to an electronic control device and a computer program product with program instructions for carrying out the method.

[0007] Current and future legislation stipulates that the emissions behavior of motor vehicles, particularly those of the internal combustion engines (ICEs) that power them and their exhaust aftertreatment systems, must be continuously monitored during operation, and any deterioration must be detected. The legislation provides for the use of so-called on-board monitoring systems (OBM systems) for this purpose.

[0008] 2. Continuously monitor the emission of pollutants into the environment at the outlet of the exhaust aftertreatment system. Legislation further requires the reliable detection of non-compliance with emission limits during real-world operation. This may also necessitate ensuring or monitoring the proper functioning of the respective on-board monitoring system.

[0009] Exhaust gas sensors are used to measure the composition of exhaust gases and, in particular, the pollutant emissions from internal combustion engines. These sensors are positioned in the exhaust stream and provide signals that are representative of the concentration of specific pollutants in the exhaust mass flow. Lambda sensors and NOx sensors are particularly relevant in this context.

[0010] Such sensors are used both for the general optimization of emissions behavior through appropriate control processes, and increasingly for the continuous monitoring of pollutant emissions during operation (On-Board Monitoring, OBM) throughout the entire life cycle of the BKM, i.e., from its initial commissioning to its final decommissioning. This On-Board Monitoring (OBM) continuously provides measurement data for assessing the BKM's emissions behavior and can be used at any time to evaluate legal compliance.

[0011] However, the exhaust gas sensors used often have the disadvantage of being cross-sensitive to other exhaust gas components and only providing a summed signal that is representative of the combined concentration of two or more pollutants in the exhaust gas mass flow. To determine the concentration fractions of individual pollutants from such a summed signal, so-called separator computational models are used, which decompose the summed signal into fractions corresponding to the concentration fractions of the individual pollutants.

[0012] For example, commercially available NOx sensors deliver a combined signal that summarizes the actual NOx and NH3 concentrations. Therefore, a separator model is required to decompose this combined signal according to the concentration fractions of these two pollutants. Such a separator model typically uses several 202401196

[0013] 3

[0014] Input variables are considered that influence the respective concentration proportions of the pollutants being sought. These input variables include, for example...

[0015] - the lambda value of the exhaust gas mass flow,

[0016] - the size of the exhaust gas mass flow

[0017] - the local exhaust gas temperature

[0018] - the fuel composition (type, quality, for example the proportions of long- and short-chain hydrocarbons)

[0019] - the condition of the exhaust aftertreatment system (aging, catalytic coating), to name just the most important ones.

[0020] The allocation of the respective concentration proportions of the pollutants can be determined via corresponding multidimensional characteristic maps stored in the control device or via corresponding stored functional structures.

[0021] Furthermore, statistical, driving profile-related, driver- or system-specific aspects can be taken into account, which may be used to correct the determined concentration proportions of pollutants.

[0022] Errors in the division of such a total signal into its individual pollutant-specific components directly lead to an error in the respective current and integrated pollutant emission masses, which are to be recorded and evaluated by the OBM (Optical Beam Management). If the errors lead to a false increase in the pollutant emission masses recorded by the OBM, the exhaust aftertreatment system may be prematurely assessed as non-compliant, even though its actual condition would still be sufficient (false failure detection). Conversely, if the errors lead to a false decrease in the pollutant emission masses recorded by the OBM, the exhaust aftertreatment system may be assessed as compliant, even though its actual condition is no longer sufficient (false compliance detection).

[0023] Compliance with legal requirements is ensured by the legislator both during the certification of a newly registered vehicle and throughout its life cycle, defined over its operating period or mileage, in 202401196

[0024] 4

[0025] Within the framework of a so-called In-Service Conformity Test (ISC test), which in future will include the verification of the respective OBM system.

[0026] Due to differing measurement accuracies between the reference measurement technology used for verification and the mass-production technology employed in the OBM system for continuous measurement during the actual, intended operation of an internal combustion engine or the corresponding vehicle, a deviation between the measurement result of the reference measurement and the measurement result of the OBM system inevitably occurs. If the deviation of the measurement results lies outside a defined tolerance band, the OBM system is considered "non-compliant with the law." This applies in particular if the measurement result of the reference measurement shows an exceedance of the limit values ​​that was not detected by the OBM system.

[0027] As has been shown, a further deviation in the pollutant emission masses determined by means of OBM can also arise in particular from the fact that, under certain boundary conditions during the operation of a BKM, condensate, for example condensate water, can accumulate in the exhaust aftertreatment device, which has the property of storing certain pollutants and releasing them again with a time delay.

[0028] Depending on the local temperatures of the exhaust aftertreatment system, condensation can occur, meaning that, for example, gaseous water escaping from the exhaust aftertreatment system condenses into a liquid on the cooler parts of the system. This can happen on the pipe walls, in the catalytic converter, particulate filter, or on any accessible surface of any component in the exhaust system that is in contact with the environment, such as on and in sensors. Such processes occur both when the exhaust gas heats up and when it cools down within the aftertreatment system. This liquid, temporarily present in the aftertreatment system, binds other exhaust gas components, such as ammonia (NH3) or hydrocarbons (CnHm). These can be pollutants that are released during such heating or cooling processes.Cooling processes would fail due to the thermal boundary conditions, resulting in the mixing of two liquids. Alternatively, the solubility of the pollutant in the first liquid could directly influence this. In both cases, the pollutants escaping from the BKM are contained in the part of 202401196.

[0029] 5

[0030] The exhaust system stores pollutants upstream of the exhaust gas sensor. The release of liquid or liquid-bound pollutants occurs with increasing local temperatures, according to the physical properties of the substances and their interactions.

[0031] The problem arising from this behavior stems from the fact that the concentration of the stored pollutant is altered and thus distorted during storage or release in relation to the concentration ratio of the pollutant concentration components determined by the exhaust gas sensor and the separator calculation model.

[0032] The present invention therefore aims to increase the accuracy of determining the emitted pollutant masses by means of an on-board monitoring system and to enable improved diagnosis of the functionality of the OBM system in order to exclude non-conformities in the ISC test as far as possible.

[0033] This problem is solved by a method, an electronic control device and a computer program product having the features according to the independent claims.

[0034] Advantageous embodiments, further developments, and details of the present invention will become apparent from the dependent claims, the description, and the drawings. These advantageous embodiments and further developments can be used individually or, provided they are not mutually exclusive, in combination with one another. Features and details described in connection with the method naturally also apply to the electronic control device and the computer program, and vice versa, so that the disclosure of this invention can always be made reciprocally with regard to the individual aspects of the invention.

[0035] According to the invention, a method for on-board determination of pollutant emission masses from an internal combustion engine with an exhaust aftertreatment device is provided. This corresponds to so-called on-board monitoring of pollutant emissions. The method is carried out by means of an electronic device assigned to the internal combustion engine and / or the exhaust aftertreatment device.

[0036] 6

[0037] Control device implemented. The electronic control device can be a central control device or a part or subsystem of a central control device of the internal combustion engine or a part or subsystem of an on-board monitoring system of a motor vehicle, as well as a separate electronic control device for carrying out the method.

[0038] As part of the process, sensor signal values ​​provided by at least one exhaust gas sensor, which are representative of a concentration of at least one pollutant in the exhaust gas stream of the internal combustion engine, are recorded by the control device.

[0039] Within the scope of the invention, sensor signal values ​​from multiple exhaust gas sensors can be provided, each representative of the concentration of a specific pollutant in the exhaust gas stream. Likewise, a single exhaust gas sensor can provide a signal that is representative of the combined concentration of several different pollutants in the exhaust gas stream. Examples of pollutants whose concentrations in the exhaust gas stream can be determined in this way include nitrogen oxides (NOx) and hydrocarbons (C). n H m ) and ammonia (NH3).

[0040] Simultaneously, a condensate calculation model is used to continuously determine the amount of condensate stored in the exhaust aftertreatment device, and based on the determined amount of condensate, and taking into account at least one further operating parameter and / or system parameter, sensor signal correction values ​​are continuously determined for the sensor signal values, which are representative of the continuous storage or release of at least one pollutant by the stored amount of condensate.

[0041] Based on the sensor signal values, corrected sensor signal values ​​are then determined using the respective sensor signal correction values. Based on these corrected sensor signal values, corrected pollutant emission values ​​are continuously determined, and the pollutant emission masses are calculated during the operation of the internal combustion engine based on the corrected pollutant emission values. 202401196

[0042] 7

[0043] Pollutant emission values ​​are, for example, values ​​for the concentration of the respective pollutant in the exhaust gas mass flow. The pollutant emission masses are then calculated during the continuous operation of the internal combustion engine based on the pollutant emission values ​​and the exhaust gas mass flow. For this purpose, values ​​of the current exhaust gas mass flow are used to determine the respective mass flow of the pollutant under consideration, i.e., the pollutant emission mass.

[0044] The pollutant emission masses thus determined can then be summed or integrated, for example, over the duration of an operating phase of the BKM or even over the entire service life of the BKM, and stored in a memory area of ​​the electronic control device. In the context of this patent application, the term "determined pollutant emission masses" refers only to corresponding values ​​representing the pollutant emission masses.

[0045] The advantages of the invention are essentially that a more accurate, realistic determination of the pollutant concentration fractions and thus the mass of pollutants emitted by an internal combustion engine during intended operation and over its lifetime, i.e. the pollutant emission masses, can be carried out by means of an on-board monitoring system.

[0046] Further advantageous embodiments and configurations of the method according to the invention are disclosed in the dependent claims, as described below.

[0047] In one embodiment of the method according to the invention, the corrected sensor signal values ​​are representative of the concentration of the sum of several pollutants contained proportionally in the exhaust gas mass flow. Based on the corrected sensor signal values, continuously corrected pollutant emission values ​​for individual pollutants are then determined using a separator calculation model, whereby the separator calculation model is also continuously adapted or corrected depending on the respective sensor signal correction values. Based on the corrected pollutant emission values, the pollutant emission masses of the individual pollutants during operation of the internal combustion engine are then determined. 202401196

[0048] 8

[0049] This approach enables a more accurate, realistic determination of the pollutant concentration proportions and thus the respective pollutant emission mass of the pollutants emitted by an internal combustion engine in normal operation, also based on sensor signal values ​​that are representative of the concentration of a sum of several pollutants contained proportionally in the exhaust gas mass flow.

[0050] In one implementation of the procedure, at least one of the following measures is initiated if the pollutant emission values ​​or the pollutant emission masses of at least one pollutant exceed a predefined threshold. These measures may include, optionally or in combination, issuing a warning or error message to the operator of the internal combustion engine, storing a warning or error message in an error memory of the electronic control device, restricting the operation of the internal combustion engine to operating ranges with low pollutant emissions, and / or shutting down the internal combustion engine. This advantageously ensures that the internal combustion engine does not exceed the legally prescribed emission limits, or only for a limited time.

[0051] In a further embodiment of the method according to the invention, the sensor signal correction values ​​are determined using at least one of the following additional operating parameters, which can influence the absorption or release of pollutants by the condensate:

[0052] - Acceleration and deceleration processes to which the exhaust aftertreatment device is subjected during operation. This can, for example, affect the distribution of condensate within the exhaust aftertreatment device and the wetting of internal surfaces of the exhaust aftertreatment device.

[0053] - The position and orientation, as well as changes in position and orientation, of the exhaust aftertreatment device within the room. This can also influence, for example, the distribution of condensate within the exhaust aftertreatment device and the wetting of internal surfaces of the exhaust aftertreatment device.

[0054] - Lateral accelerations, side forces and centrifugal forces to which the exhaust aftertreatment device is subjected during operation. This can also, for example, affect the distribution of condensate within the 202401196

[0055] 9

[0056] The exhaust aftertreatment device and the wetting of internal surfaces of the exhaust aftertreatment device may be affected.

[0057] - Strength and velocity of the exhaust gas mass flow. These determine or intensify, for example, turbulence and evaporation effects and thus the release of pollutants into the exhaust gas mass flow;

[0058] - Temperature of the exhaust gas mass flow (11a) through or over the exhaust gas aftertreatment device (2) and the surfaces formed by the condensate during operation. This can also influence evaporation effects and thus the release of pollutants into the exhaust gas mass flow;

[0059] - Thermal conditions in an interior space and on the interior surfaces of individual components or the entire exhaust aftertreatment system (2) that cause an increase or decrease in the amount of condensate. These can also influence evaporation effects and thus the release of pollutants into the exhaust gas mass flow.

[0060] Using one, several or all of the aforementioned operating parameters allows for a favorable approximation to real-world conditions and thus a more accurate, realistic determination of pollutant emission masses.

[0061] In a further embodiment of the method according to the invention, the sensor signal correction values ​​are determined using at least one of the following additional system parameters, which can influence the absorption or release of pollutants by the condensate:

[0062] - Volume and proportions of internal surfaces of individual components or the entire exhaust aftertreatment system that may be exposed to condensate. This affects, for example, the surfaces of the condensate that are flowed over by the exhaust gas mass flow.

[0063] - Geometry data of individual components or the entire exhaust aftertreatment system. These can, for example, influence the distribution of condensate in the exhaust aftertreatment system and thus also the condensate surfaces exposed to the exhaust mass flow;

[0064] - Size of the surfaces formed by the condensate and over which the exhaust gas mass flow (11 a) can flow;

[0065] - free cross-sectional areas of individual components or the entire exhaust aftertreatment device (2) through which the exhaust gas mass flow (11 a) can flow. These are, for example, decisive for the flow velocity of the exhaust gas mass flow, which in turn, for example, influences turbulence and 202401196

[0066] 10

[0067] Evaporation effects and thus the release of pollutants into the exhaust gas mass flow can be determined or increased.

[0068] Using one, several or all of the aforementioned system parameters allows for a favorable approximation to real-world conditions and thus a more accurate, realistic determination of pollutant emission masses.

[0069] It is evident that the aforementioned operating and system parameters can mutually influence each other's effect on the absorption or release of pollutants by the condensate. The corresponding values ​​of these operating parameters can be provided, for example, by appropriate sensors or computational models. The impact of these values ​​on determining the sensor signal correction values ​​can be determined, if necessary, through experimental series or simulations, or by applying pre-trained neural networks, and used to calculate the sensor signal correction values.

[0070] Many of the potentially required sizes and values ​​are already available in a modern motor vehicle, as they are needed for other vehicle-specific processes and functions.

[0071] An electronic control device according to the invention for operating an internal combustion engine with an exhaust aftertreatment device comprises at least one electronic storage device in which at least one computer program product with program instructions is provided, and an input / output interface configured for receiving and outputting electrical signals, as well as an electronic processing unit (processor) with access to the at least one electronic storage device and the input / output interface for executing the program instructions. When the program instructions are executed by means of the electronic processing unit, they cause the electronic control device to execute the method according to one of the preceding claims. The electronic control device is thus configured to execute a method according to one of the embodiments described above. 202401196

[0072] 11

[0073] The advantages of this electronic control device, like the method itself, are essentially that a more accurate, realistic determination of the mass of pollutants emitted by an internal combustion engine during normal operation and over its lifetime can be achieved using an on-board monitoring system.

[0074] A computer program product according to the invention for operating an internal combustion engine with an exhaust aftertreatment device comprises program instructions for execution by the electronic computing unit of the aforementioned electronic control device, wherein the program instructions, when executed by the electronic computing unit, cause the electronic control device to carry out the method according to one of the embodiments described above.

[0075] Here too, the advantages lie essentially in the fact that a more accurate, realistic determination of the mass of pollutants emitted by an internal combustion engine during normal operation and over its lifetime can be carried out by means of an on-board monitoring system.

[0076] The features and combinations of features of the embodiments of the invention mentioned above in the description or below in the description of the figures are to be applied individually, in part or in their entirety, also in mutual combination or mutual supplementation, in further development of the invention, without leaving the scope of the invention, insofar as they are not alternatively applicable or even mutually exclusive.

[0077] To avoid misunderstandings, it should be noted here that, in the context of the subject matter of the invention, the named quantities, values ​​and parameters, such as the determined amount of condensate, the operating parameters, the system parameters, the pollutant emission masses, the sensor signal values, the sensor signal correction values, the pollutant emission values ​​and the pollutant emission masses, etc., are to be understood as electronically or digitally processable value quantities that are representative of the named quantities, values ​​and parameters.

[0078] The figures below describe particularly advantageous embodiments, details or further developments of the invention in more detail. 202401196

[0079] 12 explains, although the subject matter of the invention is not limited to these examples.

[0080] They show:

[0081] Fig. 1 A simplified schematic representation of an internal combustion engine with exhaust aftertreatment device;

[0082] Fig. 2 A simplified flowchart illustrating the process.

[0083] Fig. 3 An overview of influencing factors on the absorption or release of pollutant fractions by the condensate in the exhaust aftertreatment device

[0084] The figures in this application are to be considered schematic only, and the relative sizes of the individual figures and the elements depicted within them are not to scale. Rather, individual elements may be exaggerated for clarity and / or to improve comprehensibility. Elements with identical functions, names, or similar effects are identified across all figures by the same reference symbols. In some figures, individual reference symbols may be omitted to improve clarity.

[0085] Figure 1 shows an internal combustion engine 1, which can be designed, for example, as a reciprocating piston engine with four cylinders (indicated). The internal combustion engine 1 is supplied with an air-fuel mixture 10a from the intake side via an air-fuel mixture supply unit 10. The air-fuel mixture supply unit 10 represents, for example, a fuel injection system in conjunction with a throttle valve, which is connected to the electronic control device 7 via signal lines 8 and is controlled in such a way that an air-fuel mixture 10a is supplied to the combustion chambers of the internal combustion engine 1 in a predetermined quantity and composition.Thus, the electronic control device, according to the program instructions contained therein, can influence both the power supplied and the composition of the exhaust gas stream 11 a, in particular the so-called lambda value, which provides information about the oxygen content in the exhaust gas stream 11 a.

[0086] On the exhaust side of the internal combustion engine 1 is connected an exhaust aftertreatment device 2 with a first exhaust catalyst 3, a second exhaust catalyst 4 and a particulate filter 5, which is connected via an exhaust pipe 11 to 202401196

[0087] 13 the internal combustion engine 1 are connected and linked together. This exhaust aftertreatment device 2 corresponds to a conventional design in a gasoline engine, but this configuration is not strictly necessary for carrying out the method according to the invention. It is explicitly pointed out that the methods and articles according to the invention can also be used with different configurations of internal combustion engines and exhaust aftertreatment devices, such as those used, for example, in diesel engines. Of particular importance, however, is the exhaust gas sensor 6c at the outlet of the exhaust aftertreatment device 2, through which the exhaust gas flow 11a is released into the environment after aftertreatment.

[0088] The exhaust gas mass flow 11a is directed through the exhaust pipe 11 to the aforementioned components of the exhaust aftertreatment device 2. The exhaust gas mass flow 11a is represented by arrow symbols indicating the direction of flow. The first exhaust catalyst 3 is located close to the engine, directly at the exhaust outlet of the internal combustion engine 1, and is designed, for example, as a three-way catalyst (TWC). Downstream of the first exhaust catalyst 3, with respect to the exhaust gas flow 11a, is a particulate filter 5, which is designed, for example, as a gasoline particulate filter (GPF), followed by the second exhaust catalyst 4, which can also be designed as a three-way catalyst (TWC) and can, for example, be arranged as a so-called underbody catalyst (UBC) on the underbody of a motor vehicle.

[0089] In the exhaust pipe 11, a first exhaust gas sensor 6a is arranged upstream of the first exhaust gas catalyst 3, a second exhaust gas sensor 6b is arranged downstream of the first exhaust gas catalyst 3, and a third exhaust gas sensor 6c is arranged downstream of the second exhaust gas catalyst 4 in the exhaust gas stream 11a. A temperature sensor 9 for measuring the temperature of the exhaust gas stream 11a is also arranged in the exhaust pipe 11 between the first exhaust gas catalyst 3 and the particulate filter 5. The pressure drop across the particulate filter 5, which provides information about the soot load of the particulate filter 5, is determined by means of a differential pressure sensor Ap.

[0090] The sensors 6a-c and 9 mentioned above are connected via electrical signal lines 8 to the input / output interface 7c of an electronic control device 7 according to the invention for transmitting the sensor signals to the 202401196

[0091] 14

[0092] Control device 7. The air-fuel mixture supply unit 10 of the internal combustion engine 1 is also connected via electrical signal lines 8 to the input / output interface 7c of the electronic control device 7 according to the invention.

[0093] The electronic control device 7 comprises an electronic computing unit 7a, also referred to as a processor, an electronic storage device 7b, and an input / output interface 7c. In this embodiment, the electronic storage device 7b includes a program memory 7b1 in which a computer program product 20 according to the invention, containing program instructions, is available. Furthermore, the electronic storage device 7b includes an operating data memory 7b2 in which predefined operating data 21, as well as operating data acquired during operation, are stored, for example, arranged in characteristic maps.

[0094] The electronic computing unit 7a is configured to carry out the method according to the invention in the embodiments described above and, if applicable, in further variations. For this purpose, the electronic computing unit 7a has access to, or is in a data connection (symbolized by connecting arrows) with, the input / output interface 7c, the program memory 7b1, and the operating data memory 7b2. When executing the program instructions, the electronic computing unit 7a uses the relevant operating and system parameters and, if applicable, various threshold values ​​for, e.g.,

[0095] Based on pollutant emission masses and the distance traveled, the electronic control device 7 is prompted to execute the inventive method for on-board determination of pollutant emission masses of an internal combustion engine 1, optionally with simultaneous lambda control of the fuel-air mixture 10a supplied to the internal combustion engine 1 during operation.

[0096] In accordance with the program instructions, sensor data or operating parameters BePa, ​​such as the signals from the exhaust gas sensors 6a-c, AS_Sig, which represent the pollutant content and / or the oxygen content in the exhaust gas stream 11a, and signals from the temperature sensor 9, are received via the input / output interface 7c and, if necessary, stored as operating data 21 in the operating data memory 7b2. The program then executes the calculations specified for on-board determination of pollutant emission masses according to the inventive method. Based on this, control commands are then issued, for example, for 202401196.

[0097] 15

[0098] Control of the air-fuel mixture 10a is output to the air-fuel mixture supply unit 10 of the internal combustion engine 1.

[0099] For the execution of the procedure for on-board determination of pollutant emission masses, in particular the sensor signal values, AS_Sig, which are provided by the exhaust gas sensor 6c and which are representative of a concentration of at least one pollutant in the exhaust gas stream 11 a of the internal combustion engine (1) released into the environment are used.

[0100] In both the first exhaust catalyst 3 and the second exhaust catalyst 4, as well as in the particulate filter 5, the deposition of condensate 12 is indicated. Figure 2 shows a highly simplified example of the process flow in an embodiment of the method according to the invention, depicted in individual process steps. The method is carried out by means of an electronic control device 7 associated with the internal combustion engine 1 and / or the exhaust aftertreatment device 2. However, the method according to the invention and its described embodiments are not to be interpreted as being limited to the process steps and relationships shown in Figure 1.

[0101] The method for on-board determination of pollutant emission masses from an internal combustion engine 1 with an exhaust aftertreatment device 2 begins, as symbolized by process step VS_1, with the control device acquiring sensor signal values ​​AS_Sig provided by at least one exhaust gas sensor 6c, which are representative of the concentration of at least one pollutant in the exhaust gas of the internal combustion engine. The exhaust gas sensor 6c is advantageously arranged at the outlet of the exhaust aftertreatment device 2, where it detects the pollutant concentration of the exhaust gas that is released into the environment.

[0102] As described in process step VS_2, a condensate quantity M_Kdst stored in the exhaust aftertreatment device 2 is continuously determined in parallel using a condensate calculation model Kdst_Mod, and a corresponding value is provided for further processing, as shown by the appropriately marked, dashed-bordered block. 202401196

[0103] 16

[0104] In the depicted process step VS_2.1, based on the determined condensate quantity M_Kdst or by using a value corresponding to the condensate quantity M_Kdst and by using at least one further operating parameter BePa and / or one further system parameter SyPa, both represented by correspondingly marked, dashed-bordered blocks, sensor signal correction values ​​AS_Sig_Kw are continuously determined for the sensor signal values ​​AS_Sig and provided as corresponding values ​​for further processing, represented by the correspondingly marked, dashed-bordered block AS_Sig_Kw, whereby these sensor signal correction values ​​AS_Sig_Kw are representative of the continuous storage or release of the at least one pollutant by the stored condensate quantity M_Kdst.

[0105] Possible operating parameters include all variable variables detectable during operation that influence the exhaust aftertreatment process, and in particular the condensate formation, the distribution of the condensate in the exhaust aftertreatment device, the evaporation of the condensate, as well as the thermal states of the components of the exhaust aftertreatment device and the condensate, which affect the continuous storage or release of at least one pollutant by the stored condensate quantity M_Kdst and thus the instantaneous pollutant concentration in the exhaust mass flow 11a.

[0106] Possible system parameters SyPa include all system-specific parameters such as size, volume, geometry, heat capacity, clear cross-sections, etc., which also influence the continuous storage or release of at least one pollutant through the stored condensate quantity M_Kdst and thus the current pollutant concentration in the exhaust gas mass flow 11a.

[0107] Based on the initially acquired sensor signal values ​​AS_Sig, corrected sensor signal values ​​AS_Sig_Korr are then determined in process step VS_1.1 using the respective sensor signal correction values ​​AS_Sig_Kw and made available for further processing within the process, as shown by the dashed-bordered block labeled AS_Sig_Korr. 202401196

[0108] 17

[0109] In the subsequent process step VS_1.2, corrected pollutant emission values ​​SEW_Korr_X are continuously determined based on the corrected sensor signal values ​​AS_Sig_Korr. If the corrected sensor signal values ​​AS_Sig_Korr are representative of only one specific pollutant, then only corrected pollutant emission values ​​SEW_Korr_X for that pollutant are provided. Based on these, the pollutant emission masses SEM_X for that pollutant are then determined in process step VS_1.3_X during the operation of the internal combustion engine 1. The corresponding values ​​of the pollutant emission masses SEM_X can then be stored and totaled in a designated storage area of ​​the operating data memory 7b2 of the electronic storage device 7b over an operating period segment or the entire operating period of the internal combustion engine 1.The data will be integrated into an overall value per pollutant and made available for monitoring compliance with legally prescribed limits.

[0110] However, if the previously determined corrected sensor signal values ​​AS_Sig_Korr are representative of the concentration of a sum of several pollutants contained proportionally in the exhaust gas mass flow (11 a), it is necessary to continuously determine the respective corrected pollutant emission value shares SEW_Korr_X...Z for the individual pollutants (X... .Z) on the basis of the corrected sensor signal values ​​AS_Sig_Korr using a separator calculation model Sep_Mod.

[0111] As described in the introduction, such a separator model, Sep_Mod, typically uses several input variables, referred to here as separator model parameters Sep_Mod_Pmtr, which influence the respective concentration fractions of the pollutants being sought. These input variables include, for example...

[0112] - the lambda value of the exhaust gas mass flow,

[0113] - the size of the exhaust gas mass flow

[0114] - the local exhaust gas temperature

[0115] - the fuel composition (type, quality, for example the proportions of long- and short-chain hydrocarbons)

[0116] - the condition of the exhaust aftertreatment system (aging, catalytic coating), and possibly other relevant parameters. For clarity, these are only symbolically summarized in Fig. 2 by the dashed-bordered block labeled Sep_Mod-Pmtr. 202401196

[0117] 18

[0118] Since the existing separator calculation models do not take into account the temporary presence of condensate in the exhaust aftertreatment device 2 and the associated pollutant deposits or releases, and since the pollutant fractions in the exhaust mass flow 11 a and thus the pollutant emission value fractions SEW_Korr_X...Z are temporarily changed as a result, it is necessary to also adapt the separator calculation model Sep_Mod used.

[0119] This is done continuously depending on the respective sensor signal correction values ​​AS_Sig_Kw, which are used as an additional separator model parameter Sep_Mod_Pmtr to adapt the separator calculation model Sep_Mod.

[0120] The respective pollutant emission masses SEM_X...Z of the individual pollutants are then determined during the operation of the internal combustion engine 1 based on the corrected pollutant emission value shares SEW_Korr_X...Z thus determined. The corresponding values ​​of the pollutant emission masses SEM_X...Z can then be stored in a designated storage area of ​​the operating data storage unit 7b2 of the electronic storage device 7b for an operating period or the entire operating period of the internal combustion engine 1 and summed or integrated into a total value per pollutant and made available for monitoring compliance with the legally prescribed limit values.

[0121] In decision step ES_1, it is determined whether the previously calculated corrected pollutant emission values ​​(SEW_Korr_X), pollutant emission value shares (SEW_Korr_X...Z), or pollutant emission masses (SEM_X...Z) exceed a respective predefined threshold. If this is the case, indicated by the decision path "yes," at least one of the following measures is initiated in the subsequent process step labeled Fe_Mass:

[0122] - Issuance of a warning or error message to an operator of the internal combustion engine

[0123] - Storing a warning or error message in an error memory of the electronic control device,

[0124] - Restriction of the operation of the internal combustion engine to operating ranges with low pollutant emissions, 202401196

[0125] 19

[0126] - Shutdown of the internal combustion engine.

[0127] If no threshold is exceeded, which is indicated by the decision path "no", the process returns to the continuous repetition of the procedure.

[0128] Figure 3 shows an overview of factors influencing the uptake or release of pollutant components by the condensate in the exhaust aftertreatment device.

[0129] 202401196

[0130] 20

[0131] Reference symbol list

[0132] 1 Internal combustion engine 2 Exhaust aftertreatment device

[0133] 3 First exhaust catalyst 4 Second exhaust catalyst 5 Particulate filter 6a - c Exhaust sensors 7 Electronic control device 7a Electronic processing unit 7b Electronic storage device 7b1 Program memory 7b2 Operating data memory 7c Input / output interface 8 Signal lines 9 Temperature sensor

[0134] 10 Air-fuel mixture supply unit 10a Air-fuel mixture 11 Exhaust pipe 11a Exhaust flow 12 Condensate 20 Computer program product 21 Operating data GPF Gasoline particulate filter Ap Differential pressure sensor TWC Three-way catalytic converter UbKat Underfloor catalytic converter

[0135] AS_Sig Sensor signal values ​​AS_Sig_Kw Sensor signal correction values ​​Fe_Mass Error measures AS_Sig_Korr Corrected sensor signal values ​​Kdst_Mod Condensate calculation model M_Kdst Condensate quantity SEW_Korr_X Corrected pollutant emission values ​​SEW_Korr_X...Z Corrected pollutant emission value components SEM_X Pollutant emission mass SEM_X...Z Pollutant emission masses of individual pollutants Sep_Mod Separator calculation model 202401196

[0136] 21

[0137] Sep_Mod_Pmtr Separator Computational Model Input Parameter

[0138] BePa operating parameters

[0139] SyPa System parameters

[0140] VS_1 to VS_2.1 Procedure steps ES_1 Decision step

Claims

1. 202401196 22 Patent claims 1. Method for on-board determination of pollutant emission masses of an internal combustion engine (1) with an exhaust aftertreatment device (2), wherein the method is carried out by means of an electronic control device (7) associated with the internal combustion engine (1) and / or the exhaust aftertreatment device (2), wherein sensor signal values ​​(AS_Sig) provided by at least one exhaust gas sensor (6c), which are representative of a concentration of at least one pollutant in an exhaust gas mass flow (11a) of the internal combustion engine (1),by the control device (7) and wherein, in parallel, a quantity of condensate (M_Kdst) stored in the exhaust aftertreatment device (2) is continuously determined using a condensate calculation model (Kdst_Mod) and, based on the determined quantity of condensate (M_Kdst), sensor signal correction values ​​(AS_Sig_Kw) are continuously determined for the sensor signal values ​​(AS_Sig) that are representative of the continuous storage or release of the at least one pollutant by the stored quantity of condensate (M_Kdst), and wherein, based on the sensor signal values ​​(AS_Sig), the respective sensor signal correction values ​​(AS_Sig_Kw) are used.corrected sensor signal values ​​(AS_Sig_Korr) are determined and, based on the corrected sensor signal values ​​(AS_Sig_Korr), corrected pollutant emission values ​​(SEW_Korr_X) are continuously determined and, in the operation of the internal combustion engine (1), the pollutant emission masses (SEM_X) are determined based on the corrected pollutant emission values ​​(SEW_Korr_X).

2. Method according to claim 1, wherein the corrected sensor signal values ​​(AS_Sig_Korr) are representative of the concentration of a sum of several pollutants contained proportionally in the exhaust gas mass flow (11a), and wherein corrected pollutant emission value fractions (SEW_Korr_X...Z) for individual pollutants are continuously determined on the basis of the corrected sensor signal values ​​(AS_Sig_Korr) using a separator calculation model (Sep_Mod), wherein the separator calculation model (Sep_Mod) is continuously updated depending on the respective sensor signal correction values ​​(AS_Sig_Kw). 202401196 23 is adjusted, and the pollutant emission masses (SEM_X...Z) of the individual pollutants in the operation of the internal combustion engine (1) are determined on the basis of the corrected pollutant emission value shares (SEW_Korr_X...Z).

3. Method according to claim 1 or 2, wherein, if the determined corrected pollutant emission values ​​(SEW_Korr_X) or pollutant emission value fractions (SEW_Korr_X...Z) or the pollutant emission masses (SEM_X...Z) of at least one pollutant exceed an assigned predetermined threshold value, at least one of the following error measures (Fe_Mass) is initiated: - Issuance of a warning or error message to an operator of the internal combustion engine - Storing a warning or error message in an error memory of the electronic control device, - Restriction of the operation of the internal combustion engine (1 ) to operating ranges with low pollutant emissions, - Shutdown of the internal combustion engine (1 ).

4. Method according to one of the preceding claims, wherein the sensor signal correction values ​​(AS_Sig_Kw) are determined using at least one of the following further operating parameters (BePa): - Acceleration / deceleration processes to which the exhaust aftertreatment device (2) is subjected during operation; - Position and orientation as well as changes in position and orientation of the exhaust aftertreatment device (2) in space; - Lateral accelerations, side forces and centrifugal forces to which the exhaust aftertreatment device (2) is subjected during operation; - Strength and velocity of the exhaust gas mass flow (11 a); - Temperature and velocity of the exhaust gas mass flow (11 a) which flows through or over the exhaust gas aftertreatment device (2) and surfaces formed by the condensate during operation; - thermal conditions in an interior space and on the interior surfaces of individual components or the entire exhaust aftertreatment device (2) that cause an increase or decrease in the amount of condensate.

5. Method according to one of the preceding claims, wherein the sensor signal correction values ​​(AS_Sig_Kw) are determined using 202401196 24 at least one of the following additional system parameters (SyPa): - Volume contents and proportions of internal surfaces of individual components or of the entire exhaust aftertreatment device (2) that may be exposed to condensate; - Geometry data of individual components or of the entire exhaust aftertreatment device (2); - Size of the surfaces formed by the condensate and over which the exhaust gas mass flow (11 a) can flow; - free cross-sectional areas of individual components or the entire exhaust aftertreatment device (2) through which the exhaust gas mass flow (11 a) can flow.

6. Electronic control device (7) for operating an internal combustion engine (1) with an exhaust aftertreatment device (2), with at least - an electronic storage device (7b) in which at least one computer program product (20) containing program instructions is provided and - an input / output interface (7c) designed to receive and output electrical signals, as well as - an electronic computing unit (7a) for executing the program instructions, with access to the at least one electronic storage device (7b) and the input / output interface (7c); wherein the program instructions, when executed by means of the electronic computing unit (7a), cause the electronic control device (7) to execute the method according to one of the preceding claims.

7. Computer program product (20) for operating an internal combustion engine (1) with an exhaust aftertreatment device (2), comprising program instructions for execution by the electronic computing unit (7a) of the electronic control device (7) according to claim 6, wherein the program instructions, when executed by the electronic computing unit (7a), cause the electronic control device (7) to carry out the method according to any one of claims 1 to 5.

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