Method for operating a motor vehicle which can be driven by an internal combustion engine, and corresponding motor vehicle

Abstract

The invention relates to a method for operating a motor vehicle (1) which can be driven by an internal combustion engine (2) and which comprises an exhaust-gas apparatus (3) for emitting exhaust gas from the internal combustion engine (2) and at least one sensor unit (4), the method comprising the following steps: - acquiring operating data from the internal combustion engine and / or the exhaust-gas apparatus by means of the sensor unit; (S1) - modelling a current particle emission present in the exhaust gas on the basis of the operating data and / or at least one correction value by a modelling unit (6); (S2) - estimating the cumulative route emission for a route on the basis of the modeled current particle emission; (S3) - identifying an availability value on the basis of a comparison of the route emission with an emission budget for the route. (S4) - On the basis of the availability value: determining an operating mode of the motor vehicle (1) by means of which the route emission can be reached within the emission budget; (S5) and - operating the motor vehicle (1) by means of the determined operating mode. (S6) The invention also relates to a motor vehicle (1).

Description

[0001] Method for operating a motor vehicle driven by an internal combustion engine and corresponding motor vehicle

[0002] The invention relates to a method for operating a motor vehicle driven by an internal combustion engine according to patent claim 1. Furthermore, the invention relates to a motor vehicle comprising an internal combustion engine and an exhaust system according to patent claim 10.

[0003] Motor vehicles generate emissions, particularly those produced as exhaust gases by internal combustion engines, such as gasoline or diesel engines, used to power the respective vehicle. Extremely low emissions are desirable when operating a motor vehicle. Furthermore, there are regulations or legal requirements that specify a maximum emission limit for a motor vehicle.

[0004] DE 10 2021 103 944 A1 shows a method for operating an internal combustion engine of a motor vehicle, wherein an engine operating value is determined.

[0005] The object of the present invention is to provide a method for operating a motor vehicle and the corresponding motor vehicle, by means of which in particular an emission can be continuously determined and, if the emission is of a corresponding magnitude, countermeasures can be initiated to reduce the same.

[0006] This object is achieved according to the invention by the subject matter of the independent patent claims. Advantageous embodiments and further developments of the invention are the subject matter of the dependent patent claims, the description, and the drawings.

[0007] A first aspect of the invention relates to a method for operating a motor vehicle driven by an internal combustion engine, which has an exhaust device for expelling exhaust gas generated by the operation of the internal combustion engine, and at least one sensor unit designed to detect operating data of the internal combustion engine and / or the exhaust device.

[0008] The internal combustion engine is an internal combustion engine, for example a diesel engine and in particular a gasoline engine. The motor vehicle can be designed in particular as a passenger car or a truck. The exhaust system comprises, for example, an exhaust system and can furthermore have a catalytic converter and / or a corresponding particulate filter, such as a gasoline particulate filter. The sensor unit serves to record operating data which, in particular, characterize a current operating state of the internal combustion engine and / or the exhaust system and thus of the motor vehicle. For this purpose, the sensor unit can, for example, detect a NO x -Sensor and / or a lambda probe, by means of which, for example, nitrogen and / or oxygen concentration in the exhaust gas can be determined.

[0009] In order for the method to be used advantageously to operate the motor vehicle, the method comprises the following steps:

[0010] A first step is the recording or determination of the operating data that characterize the internal combustion engine and / or the exhaust system by the sensor unit.

[0011] In a second step, a particle emission currently present in the exhaust gas is modeled by a modeling unit on the basis of the operating data and / or at least one control value, which corresponds, for example, to a control specification from a user or from a driver assistance system and describes a set state of an engine parameter or operating parameter of the internal combustion engine, wherein a particle quantity and / or a particle size are determined for the particle emission by the modeling.

[0012] In a third step, the cumulative route emissions for a route are estimated, in particular calculated, based on the modeled current particle emissions.

[0013] In a fourth step, an available value is determined based on a comparison of the route emissions with an emissions budget for the route. In a fifth step, depending on the determined available value, an operating state of the motor vehicle, in particular of the internal combustion engine and / or the exhaust system, is determined, through which the route emissions can be achieved or maintained within the emissions budget.

[0014] In a sixth step, the motor vehicle is operated using the determined operating state.

[0015] The modeling can be carried out using a model that describes the internal combustion engine and its exhaust gas emissions or a possible influence of the exhaust system on the exhaust gas, and can be simulated, for example. For example, the modeling unit can comprise and / or be executed by an electronic computer. Particle emissions describe the emission of particles and are described by the quantity and size of particles present in the exhaust gas, such as soot. A permitted level of particle emissions for a distance traveled can be specified, for example, by a country-specific regulation. This can result in the emissions budget, which describes how much particle emission is permitted for the distance traveled or can be emitted through the exhaust gas.

[0016] By modeling the current particulate emissions, the distance emissions for the route can be estimated, from which the available value can be determined, which indicates how much particulate emissions are still available for the distance to be driven. The distance traveled thus describes, in particular, the distance traveled or the distance that can be covered during the journey. If the modeling shows that the emissions budget cannot be met or is exceeded with the current operating state of the internal combustion engine or the current driving style, the method according to the invention determines an operating state suitable for meeting the emissions budget for the route.

[0017] In other words, a method for real-time modeling of exhaust emissions with respect to particle number and / or particle mass is provided. For example, the particle emissions are determined by combining real-time modeling of the particle emissions of the internal combustion engine and modeling, for example, the loading of the particulate filter. Based on the modeled particle number and particle mass, possible reactive measures for the operation of the internal combustion engine, such as an injection strategy, can be initiated.

[0018] The method according to the invention thus offers the advantage of reducing motor vehicle emissions. Furthermore, a predefined emissions budget can be observed, so that a desired potential exhaust gas or particulate emission level can be estimated and, in particular, adhered to for a given distance.

[0019] In an advantageous embodiment of the invention, the exhaust system comprises a gasoline particulate filter. In other words, the exhaust system has a particulate filter which, particularly due to its design, which advantageously comprises a highly porous and heat-resistant ceramic, is designed to bind particles contained in the exhaust gas, and in particular soot particles, to its surface. This results in the advantage that the motor vehicle can be operated particularly advantageously when the internal combustion engine is designed as a gasoline engine.

[0020] In an advantageous embodiment of the invention, when a gasoline particulate filter is used for modeling by the modeling unit, a gasoline particulate filter model is provided. In other words, a particularly existing or known model that describes the behavior of a gasoline particulate filter is used when modeling the particle emissions by the modeling unit, wherein the modeling unit can thus create a model for modeling the particle emissions that includes the gasoline particulate filter model. This results in the advantage that the modeling unit can be designed in a modular manner, thus enabling, for example, simple adaptation when the model for the gasoline particulate filter is updated. In this way, real-time modeling of the current particle emissions can be carried out particularly precisely.This also results in the advantage that the motor vehicle can be operated particularly advantageously, since its emissions can be described particularly advantageously.

[0021] In an advantageous embodiment of the invention, a NOx sensor and / or a lambda probe are used as the at least one sensor unit. In other words, the sensor unit comprises a nitrogen oxide sensor designed to detect nitrogen oxides in the exhaust gas. The nitrogen in the exhaust gas can contain both nitrogen monoxide and nitrogen dioxide and / or other nitrous gases, which are similar to the NO x -Sensor can detect. The NO xThe sensor can, for example, be designed as a dual-chamber sensor located on the catalytic converter. The lambda sensor is a sensor that measures the oxygen concentration, particularly the residual oxygen content, in the exhaust gas and thus allows conclusions to be drawn about the mixture of oxygen and fuel in the combustion engine. Thus, both the NO x Both the sensor and the lambda sensor are well-suited to providing operating data, which can be used to model current particulate emissions particularly effectively. This has the advantage of allowing the available value to be determined particularly effectively.

[0022] In a further advantageous embodiment of the invention, the modeling unit is implemented by digital engine electronics. In other words, the modeling unit is a component of an engine control system, which can be formed by an electronic control unit. The engine control system regulates, for example, fuel injection into the internal combustion engine, which can, for example, describe an operating state determined by the method. This results in the advantage that the method can be implemented particularly efficiently, since, for example, the modeling of the emissions and the determination of the operating state can be performed by a single unit.

[0023] In an advantageous embodiment of the invention, the at least one manipulated variable and / or the operating data characterizes a load, an engine map, a state of an injection system, a state of a turbocharger and / or a variable valve control. In other words, the manipulated variable describes a parameter set by open-loop or closed-loop control for the internal combustion engine and thus predetermined, which can be, for example, the injection, the charging of the turbocharger and / or the setting of a valve. The operating data can include information that allows conclusions to be drawn about the parameters. This results in the advantage that parameters that have a known effect on particulate emissions can advantageously be incorporated into the modeling. This results in the advantage that the method allows particularly precise statements about particulate emissions based on the processes in the internal combustion engine.

[0024] In a further advantageous embodiment of the invention, the route is specified by a navigation system and / or estimated using the vehicle speed. In other words, the motor vehicle has a navigation system or is connected to it, and this is designed for data exchange with the modeling unit and / or the digital engine electronics. In particular, data from the navigation system can be read in by the modeling unit and / or the engine electronics. In this way, when modeling using specifications, for example based on route planning by the navigation system, the route can be determined in a particularly advantageous manner and thus the emissions budget can be advantageously determined. Additionally or alternatively, the emissions budget can be estimated, in particular, by means of an integral over the vehicle speed during the journey.This has the advantage that the disposal value can be determined particularly precisely.

[0025] In a further advantageous embodiment of the invention, route sections in which the motor vehicle is electrically powered are taken into account for the cumulative route emissions. In other words, when cumulating the particulate emissions to the route emissions, it is taken into account whether there are any sections along the route in which the motor vehicle, being a hybrid vehicle, is powered electrically—for example, by battery-electric power and / or a fuel cell. Lower particulate emissions are to be expected on these route sections, although these are not caused by the internal combustion engine. This allows a corresponding adjustment to the available value. This has the advantage that the motor vehicle can be operated particularly efficiently and / or with particularly high performance.

[0026] In an advantageous embodiment of the invention, a mixture type, an injection strategy and / or exhaust gas mass flow is specified and / or a specified range of an engine characteristic map is set as the operating state suitable for achieving the emissions budget. Thus, by changing the injection, an attempt is made to influence the emissions budget to be achieved. In other words, the combustion air ratio for the operation of the internal combustion engine and thus for the operation of the motor vehicle is specified so that, for example, depending on the determined available value, a switch can be made from a rich mixture to a lean mixture. Additionally or alternatively, the internal combustion engine or the combustion engine can be operated in a range according to its engine characteristic map for which particulate emissions are known to be low.This provides the advantage that particle emissions can be easily controlled without negatively impacting the operation of the motor vehicle. A second aspect of the invention relates to a motor vehicle having an internal combustion engine and an exhaust system for expelling exhaust gas from the internal combustion engine, and having at least one sensor unit configured to detect operating data of the internal combustion engine and / or the exhaust system, wherein the motor vehicle is configured to carry out a method according to the first aspect of the invention.

[0027] Advantages, advantageous embodiments and further developments of the first aspect of the invention are to be regarded as advantages, advantageous embodiments and further developments of the second aspect of the invention and vice versa.

[0028] Further features of the invention emerge from the claims, the figures, and the description of the figures. The features and combinations of features mentioned above in the description, as well as the features and combinations of features mentioned below in the description of the figures and / or shown alone in the figures, can be used not only in the respective specified combination, but also in other combinations or on their own.

[0029] The invention will now be explained in more detail using a preferred embodiment and with reference to the drawings. It shows:

[0030] Fig. 1 is a schematic flow diagram of a method for operating a motor vehicle; and

[0031] Fig. 2 a motor vehicle which is used to carry out the method according to

[0032] Fig. 1 is formed.

[0033] Fig. 1 shows a schematic flow diagram for a method for operating a motor vehicle 1 which can be driven by an internal combustion engine 2 and which has an exhaust device 3 for expelling exhaust gas from the internal combustion engine 2 and at least one sensor unit 4 which is designed to record operating data of the internal combustion engine and / or the exhaust device.

[0034] The method makes it possible to detect a particle emission which is contained in the exhaust gas through the exhaust system 3, which in particular has an exhaust system 9 and a gasoline particle filter 5, and to operate the motor vehicle accordingly depending on an emission.

[0035] The procedure presented here comprises six steps S1 to S6:

[0036] In step S1, the operating data of the internal combustion engine 2 and / or the exhaust system 3 is recorded or determined by the sensor unit 4. In step S2, a particle emission currently present in the exhaust gas is modeled, which includes a particle quantity and a particle size, which are thus each determined during modeling, based on the operating data and / or at least one target value by a modeling unit 6. In step S3, the cumulative route emission for a driving route is estimated based on the modeled, current particle emission. In step S5, an available value is determined based on a comparison of the route emission with an emission budget for the driving route.In step S5, an operating state of the motor vehicle 1, in particular its internal combustion engine 2, is determined based on the available value determined in step S4. The determined operating state enables the route emissions to be achieved within the emissions budget. In step S6, the motor vehicle is operated using the operating state determined in step S5.

[0037] Fig. 2 shows the motor vehicle 1, which is designed to carry out the method shown in Fig. 1, wherein the motor vehicle 1 comprises the internal combustion engine 2 or an internal combustion engine and the exhaust system 3 for expelling particulate matter in the exhaust gas of the internal combustion engine 2, wherein the exhaust gas contains the particulate matter emission. For the motor vehicle 1, which is designed to carry out the method presented in Fig. 1, it can be advantageous if the modeling unit 6 is implemented or provided by digital engine electronics 7. The digital engine electronics 7 can in particular be an engine control unit, which can have an electronic computing device.The electronic computing device can thus be designed to form the modeling unit 6, wherein the operating data can be exchanged via a suitable interface, for example with the sensor unit 4 and / or the control values ​​can be exchanged, for example with operating units.

[0038] The least of a control value, which is particularly used by a user of the

[0039] The control value, which can be specified by a motor vehicle based on the operation of control elements, for example, an accelerator pedal, can describe or characterize a current state of the internal combustion engine, which is designed in particular as a gasoline engine, but can also be designed as a diesel engine. Thus, the at least one control value or the operating data can characterize a load of the internal combustion engine, an engine characteristic map thereof, a state of an injection system, regardless of whether direct injection and / or intake manifold injection is present, and the state of a turbocharger and / or a variable valve control.

[0040] Advantageously, a model which is used to model the current particulate emission present in the exhaust gas and is executed by the modeling unit comprises a special model for the gasoline particulate filter - a gasoline particulate filter model.

[0041] The sensor unit 4 advantageously comprises a NO x -Sensor and / or a lambda sensor, so that the NOx sensor and / or the lambda sensor can be used to determine or record the operating data. The NOx sensor can therefore determine a concentration of nitrogen oxides in the exhaust gas as operating data. The lambda sensor can determine the presence of residual oxygen in the exhaust gas. This means that the NOx sensor and the lambda sensor can be used to draw conclusions that are advantageous when modeling the current particle emissions, since this allows a particle quantity and / or particle size in the exhaust gas to be at least estimated, particularly using a model from the modeling unit 6.

[0042] Advantageously, the motor vehicle 1 comprises a navigation system 8, by which the route can be specified or a user's route planning can be taken into account if this is available in the navigation system 8. Thus, if the route is known, the emissions budget or the available value can be advantageously adjusted.

[0043] Furthermore, if the motor vehicle 1 is a hybrid vehicle, it has also proven advantageous to take route sections where it is known that the motor vehicle 1 is powered by a fuel cell or battery-electric power as an alternative to the internal combustion engine 2, for example. This can be taken into account when determining the available value. In this way, the motor vehicle 1 can be operated at particularly high power if necessary and still adhere to the emissions budget. If it turns out that the available value, which describes the amount and size of particles that can be emitted during the route, has reached a value which, given the current operating state of the motor vehicle 1, would result in the emissions budget being exceeded, the new operating state is determined.The new operating mode is determined or specified in such a way that a reduction in particulate emissions is possible without exceeding the emissions budget. Motor vehicle 1 is then operated in this operating mode.

[0044] It is advantageous to specify and adjust the determined operating state in such a way that a mixture type, i.e., a rich and / or lean mixture, an injection strategy, and / or, for example, an exhaust gas mass flow, is specified. The exhaust gas mass flow directly affects the particulate flow and thus the particulate emissions. Furthermore, a predefined range of an engine map can be set, particularly if the engine map is known and thus, for example, areas are known in which the particulate emissions are lower than, for example, the currently determined emissions.

[0045] By means of the presented method and the motor vehicle 1, a particle emission of the motor vehicle 1 can be regulated in a particularly advantageous manner and, in addition, the motor vehicle 1 can be operated with particularly low emissions.

[0046] List of reference symbols

[0047] motor vehicle

[0048] internal combustion engine

[0049] Exhaust system

[0050] Sensor device

[0051] Gasoline particulate filter

[0052] Modeling unit

[0053] Engine electronics or engine control unit

[0054] navigation system

[0055] Exhaust system first step second step third step fourth step fifth step sixth step

Claims

Patent claims 1. A method for operating a motor vehicle (1) driven by an internal combustion engine (2), which has an exhaust device (3) for expelling exhaust gas from the internal combustion engine (2) and at least one sensor unit (4) designed to detect operating data of the internal combustion engine (2) and / or the exhaust device (3), the method comprising the following steps: Recording the operating data of the internal combustion engine and / or the exhaust system by means of the sensor unit; (S1) Modelling a current particle emission present in the exhaust gas, which is determined on the basis of the operating data and / or at least one control value by a modelling unit (6), wherein a particle quantity and a particle size are determined for the particle emission by the modelling; (S2) Estimation of the cumulative route emissions for a route based on the modeled, current particle emissions; (S3) Determining an available value based on a comparison of the route emissions with an emissions budget for the route. (S4) Depending on the available value: Determining an operating state of the motor vehicle (1) through which the route emissions can be achieved within the emissions budget; (S5) and Operating the motor vehicle (1) using the determined operating state. (S6) 2. Method according to claim 1, characterized in that the exhaust device (3) comprises a gasoline particle filter (5).

3. Method according to claim 2, characterized in that a gasoline particle filter model is provided to the modeling unit (6) for modeling the gasoline particle filter (5).

4. Method according to one of the preceding claims, characterized in that the at least one sensor unit is a NO x -Sensor and / or a lambda sensor can be used.

5. Method according to one of the preceding claims, characterized in that the modeling unit (6) is implemented by digital engine electronics (7).

6. Method according to one of the preceding claims, characterized in that the at least one control value and / or the operating data characterize a load, an engine characteristic map, a state of an injection system, a turbocharger and / or a variable valve control.

7. Method according to one of the preceding claims, characterized in that the route is specified by a navigation system (8) and / or by means of an estimated vehicle speed.

8. Method according to one of the preceding claims, characterized in that for the cumulative route emission, route sections are taken into account in which the motor vehicle (1) is electrically driven.

9. Method according to one of the preceding claims, characterized in that a mixture type, an injection strategy and / or exhaust gas mass flow is specified by the determined operating state and / or a specified range of an engine characteristic map is set.

10. Motor vehicle (1) comprising an internal combustion engine (2) and an exhaust device (3) for expelling exhaust gas from the internal combustion engine (2), and comprising at least one sensor unit (4) which is designed to is operating data of the internal combustion engine (2) and / or the exhaust system (3), and the motor vehicle (1) is designed to carry out a method according to one of the preceding claims.

Images