DE102019008953A1 - Method for operating an exhaust gas aftertreatment device of a motor vehicle, in particular a motor vehicle - Google Patents

Abstract

The invention relates to a method for operating an exhaust gas aftertreatment device of a motor vehicle through which exhaust gas from an internal combustion engine can flow and which has at least one particle filter, a future period of time during which fired operation of the internal combustion engine will not take place is forecast as a function of at least one route of the motor vehicle ahead of the motor vehicle, wherein a regeneration of the particle filter is carried out at least during part of the time period as a function of the predicted time period.

Description

The invention relates to a method for operating an exhaust gas aftertreatment device of a motor vehicle, in particular a motor vehicle, according to the preamble of claim 1.

Such a method for operating an exhaust gas aftertreatment device of a motor vehicle, in particular a motor vehicle, is, for example, already DE 10 2016 014 255 A1 as known. Exhaust gas from an internal combustion engine of the motor vehicle can flow through the exhaust gas aftertreatment device and has at least one particle filter, by means of which any particles contained in the exhaust gas, in particular soot particles, can be filtered out of the exhaust gas.

The object of the present invention is to further develop a method of the type mentioned at the beginning in such a way that particularly low-emission operation can be implemented.

This object is achieved by a method with the features of claim 1. Advantageous configurations with expedient developments of the invention are specified in the remaining claims.

In order to further develop a method of the type specified in the preamble of claim 1 in such a way that particularly low-emission operation can be implemented, it is provided according to the invention that, in particular by means of an electronic computing device, in particular of the motor vehicle, depending on at least one ahead of the motor vehicle and thus in the near future the motor vehicle is likely to travel a distance of the motor vehicle to be traveled over a future period of time, which is predicted, that is to say predicted or estimated. During the period of time, there is no fired operation of the internal combustion engine, in particular continuously, in particular without interruption, so that no combustion processes take place in the internal combustion engine during the, in particular the entire, period of time. The period of time does not necessarily have to occur. The time span is estimated or predicted so that the time span will occur with a certain probability in the future. The feature that the time span is a future time span can in particular be understood to mean that the time span is forecast, for example, at a first point in time or during a time interval, the time span following the first point in time or the time interval. Thus, the time span with respect to the first point in time or with respect to the time interval is in the future.

A regeneration of the particle filter is carried out at least during part of the period of time as a function of the predicted period of time. Regeneration is to be understood as meaning that particles, in particular soot particles, which are received and thus stored in the particle filter, are at least partially removed from the particle filter, that is to say are stored out. For this purpose, the particle filter is heated, for example. The regeneration can thus be understood to mean a partial regeneration of the particle filter, as a result of which only a part of the particle stored in the particle filter is removed from the particle filter by the partial regeneration. The regeneration can also be understood as a complete regeneration or complete cleaning of the particle filter, which is regenerated in the context of the complete cleaning in such a way that the particles stored in the particle filter are at least predominantly, preferably completely, removed from the particle filter.

The method is carried out, for example, while driving, in particular while driving the motor vehicle electrically, which motor vehicle is driven purely electrically by means of at least one electrical machine during electrical driving. The internal combustion engine is thus deactivated during the electric drive, the time period being at least part of the electric drive. The particle filter is thus regenerated while the motor vehicle is being driven purely electrically and while the internal combustion engine is deactivated and, in particular, is at a standstill.

The time span ends, for example, at an end point in time at which the internal combustion engine is started, that is, it is switched to its fired operation. Starting the internal combustion engine is also referred to as starting, starting the engine, restarting or restarting and is associated with the end of the time period. It is preferably provided that the end time, in particular by means of the electronic computing device, is predicted, that is to say predicted, as a function of the route ahead of the motor vehicle.

The route ahead of the motor vehicle is determined, for example, by means of a navigation device, in particular the motor vehicle, and preferably on the basis of a planned route of the motor vehicle. Furthermore, the route ahead of the motor vehicle is determined, for example, at a current position of the motor vehicle on earth, the current position of the motor vehicle on earth being determined, for example, by means of a navigation device.

In the context of the method according to the invention, information is generated, for example, by using information about the route ahead, in particular for an engine control device for controlling and / or regulating the internal combustion engine. The latter include, for example, the period of time also referred to as duration or duration. The time span is an anticipated time span, since the time span has not yet occurred but is forecast. The information that is generated for the engine control unit also includes, for example, the predicted end time at which the internal combustion engine starts. Furthermore, it is preferably provided that, depending on the driving route ahead, the electronic computing device predicts a power to be provided by the internal combustion engine at one end of the time span and thus at the end time and also referred to as power output. In other words, the power is a power to be provided by the internal combustion engine when it is restarted, provision preferably that the particle filter is also regenerated as a function of the predicted end time and / or as a function of the predicted power output.

With the help of the information about the route ahead of the motor vehicle and thus the future route, the regeneration of the particulate filter, which is designed as partial cleaning or full cleaning, for example, can be targeted to phases in which the internal combustion engine is deactivated by means of intelligent control and / or regulation. To regenerate the particle filter, methods can be used which, for example, from the DE 10 2016 014 254 A1 and from the DE 10 2016 014 255 A1 are known, the disclosure and content of which are to be viewed in their entirety as part of the present disclosure. Alternatively or additionally, a catalytic burner, in particular with a freely controllable air supply, can be used to heat the particle filter by means of the catalytic burner and thereby regenerate it.

The method makes it possible, in particular, to advantageously regenerate the particle filter while the internal combustion engine is deactivated. The particle filter can thus be regenerated completely independently of the internal combustion engine by means of the method according to the invention. In addition, the information about the route ahead, also referred to as route information, can be used to forecast the period of time during which the internal combustion engine is deactivated, i.e. to predict, for example, during a further period of time preceding the period of time, while the internal combustion engine is running is in their fired operation to specifically start or carry out a regeneration of the particle filter, for example designed as partial cleaning, and thereby introduce thermal energy into the exhaust gas aftertreatment device or in an exhaust gas tract comprising the exhaust gas aftertreatment device and through which the exhaust gas of the internal combustion engine can flow, which is also referred to as an exhaust system then, for example, to regenerate the particle filter at least during the part of the time period following the further time period, in particular to the end of r Generate e while the internal combustion engine is deactivated. Thus, for example, the regeneration of the particle filter started within the further time period and carried out, for example, during the further time period, in particular continuously or without interruption, at least during the part of the further time period following the further time period, so that the particle filter partially during the fired operation of the Internal combustion engine and is partially regenerated during or within the period of time during which the internal combustion engine is deactivated.

• - Gewährleistung eines vorteilhaften Betriebs der auch als Abgasreinigungssystems bezeichneten Abgasnachbehandlungseinrichtung
• - Reduzierung des Kraftstoffverbrauchs und der Emissionen im Vergleich zu herkömmlichen Lösungen
• - Brennverfahrens unabhängige Nutzung, sodass das Verfahren auch bei Ottomotoren genutzt werden kann
• - Reinigung oder Teilreinigung des beispielsweise als Dieselpartikelfilter ausgebildeten Partikelfilters autark oder teilautark von der Verbrennungskraftmaschine
• - Möglicher Entfall eines Regenerationsbrennverfahrens zur verbrennungsmotorischen Regeneration des Partikelfilters.

In particular, the following advantages can be realized by means of the invention:

• - Ensuring an advantageous operation of the exhaust gas aftertreatment device, also referred to as an exhaust gas cleaning system
• - Reduction in fuel consumption and emissions compared to conventional solutions
• - Use independent of the combustion process, so that the process can also be used in gasoline engines
• - Cleaning or partial cleaning of the particulate filter embodied, for example, as a diesel particulate filter, self-sufficient or partially self-sufficient from the internal combustion engine
• - Possible omission of a regeneration combustion process for the combustion engine regeneration of the particle filter.

Further advantages, features and details of the invention emerge from the following description of preferred exemplary embodiments and on the basis of the drawing. 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 respectively specified combination, but also in other combinations or alone, without the scope of the Invention to leave.

• 1 ein Flussdiagramm zum Veranschaulichen eines erfindungsgemäßen Verfahrens zum Betreiben einer Abgasnachbehandlungseinrichtung eines Kraftfahrzeugs;
• 2 ein weiteres Flussdiagramm zum weiteren Veranschaulichen des Verfahrens; und
• 3 ein weiteres Flussdiagramm zum weiteren Veranschaulichen des Verfahrens.

The drawing shows in:

• 1 a flowchart to illustrate a method according to the invention for operating an exhaust gas aftertreatment device of a motor vehicle;
• 2 a further flow chart to further illustrate the method; and
• 3 a further flow chart to further illustrate the method.

Identical or functionally identical elements are provided with the same reference symbols in the figures.

In the following, using 1 to 3 a method for operating an exhaust gas aftertreatment device of a motor vehicle, in particular a motor vehicle, is described. In its completely manufactured state, the motor vehicle comprises the exhaust gas aftertreatment device and an internal combustion engine by means of which the motor vehicle can be driven. For this purpose, the internal combustion engine is operated in its fired mode, during which combustion processes take place in the internal combustion engine. The vehicle also has an exhaust gas tract through which exhaust gas from the internal combustion engine can flow and in which the exhaust gas aftertreatment device is arranged. The exhaust gas can thus flow through the exhaust gas aftertreatment device. The exhaust gas aftertreatment device has at least one particle filter embodied, for example, as a diesel particle filter, by means of which particles contained in the exhaust gas, in particular soot particles, can be filtered out of the exhaust gas. Here, the particle filter picks up the particles from the exhaust gas, so that the particles are at least temporarily stored in the particle filter. As the amount of particles stored in the particle filter increases, so-called loading of the particle filter increases. In other words, the amount of particles stored in the particle filter is also referred to as the loading of the particle filter.

In the method, a route of the motor vehicle ahead of the motor vehicle is determined, in particular by means of an electronic computing device, for example the motor vehicle. The route is determined, for example, using a route of the motor vehicle planned by means of a navigation device, in particular the motor vehicle, and on the basis of a current position of the motor vehicle on earth, the current position of the motor vehicle on earth being determined by means of the navigation device.

Depending on the determined route ahead of the motor vehicle, the electronic computing device predicts a future period of time during which the internal combustion engine will not operate continuously or without interruption. A regeneration of the particulate filter is carried out as a function of the predicted time span, at least during part of the time span and thus while the internal combustion engine is deactivated. The method is carried out, for example, while the motor vehicle is driving, wherein the time span can be at least part of the journey. The trip is, for example, an electric trip of the motor vehicle, preferably designed as a hybrid vehicle, which is driven purely electrically by means of at least one electric machine during the electric trip. The internal combustion engine is thus deactivated during electric travel.

With a block 10 a current loading of the particle filter, also referred to as soot loading, is determined, in particular via a loading model and / or based on a differential pressure sensor, by means of which, for example, a difference between a pressure prevailing in the exhaust tract upstream of the particle filter and a pressure downstream of the particle filter is determined, in particular is captured. With a block 12th information about the route ahead of the motor vehicle and thus future route is evaluated. The information characterizes the route ahead or several routes ahead of the motor vehicle. With a block 14th it is determined how long, for example, the next forecast electric trip will last. Thus, for example, in the case of the block 14th the aforementioned time span during which the internal combustion engine is deactivated and the motor vehicle is driven purely electrically. With a block 16 it is checked whether the next forecasted electric trip, i.e. the forecasted time span, is long enough to carry out a regeneration of the loaded, fully loaded or partially loaded particle filter during the time span or within the time span, designed for example as a complete or partial cleaning. If the period of time is not long enough, the method ends with a block 18th where nothing further is done. If the period of time is sufficiently long to carry out a desired or sufficient regeneration of the particle filter, for example in the form of a complete or partial cleaning, then in the case of a block 19th checks whether the period of time is long enough to carry out a complete regeneration of the particle filter, also known as complete cleaning. If this is the case, for a block 20th the complete cleaning of the particle filter is carried out, which regenerates as part of the complete cleaning in such a way that the particles absorbed in the particle filter and thus stored particles are at least predominantly, in particular completely, removed from the particle filter. In particular, complete cleaning can be understood to mean that the particles stored in the particle filter are removed from the particle filter to the greatest possible extent.

However, if the period of time is not long enough for a complete cleaning of the particle filter, then in the case of a block 21 a partial cleaning of the particle filter is carried out. With partial cleaning, the particles are only partially removed from the particle filter. The complete cleaning of the block 20th or the partial cleaning of the block 21 is carried out at least during the aforementioned part of the time span and thus within the time span, so that the complete or partial cleaning is carried out during or within the electric drive and thus then while the internal combustion engine is deactivated.

To regenerate the particle filter, the particle filter is heated, for example, by means of at least one heating element. The heating element is, for example, a burner, in particular a catalytic burner. For example, by means of a device which is different from the internal combustion engine and which is additionally provided and which can be or is operated independently of the internal combustion engine, a gas flow, for example in the form of an air flow and comprising at least partially or exclusively air, is generated, which flows at least through the particle filter. For example, the gas flow is heated by means of the heating element, so that the particle filter is heated by means of the gas flow and is thereby regenerated.

The regeneration of the particle filter can ensure that from the end of the period of time at the end of which the internal combustion engine is activated, i.e. started and thus switched to its fired operation, the particle filter can particularly advantageously filter out any particles contained in the exhaust gas from the exhaust gas. In particular, it can be ensured by the method that the particle filter already has a sufficient storage capacity from the end of the time period in order to filter particles out of the exhaust gas. This ensures particularly low-emission operation.

2 shows a further flowchart, on the basis of which a generation of forecast data for the use of information about the route is described below. In 2 illustrates a block 22nd Navi data, that is to say navigation data, which are provided, for example, by a navigation device. The navigation data includes, for example, GPS data (GPS - Global Positioning System) and / or ADAS data. The navigation data includes, for example, information about a possible city, a terrain topology, a speed and / or a destination. A block 24 illustrates, for example, a central drive train control unit for operating, in particular regulating or controlling, a drive train of the motor vehicle, the central drive train control unit also being referred to as a central powertrain controller (CPC). By the block 24 For example, signal processing takes place, in the context of which the navigation data is converted into performance data. A block 26th illustrates, for example, the aforementioned engine control unit, which uses the predictive performance data. A block 28 illustrates a use of the performance data. For example, in the case of the block 28 an estimate of how long the internal combustion engine can remain deactivated in its unfired operation or when the internal combustion engine must be reactivated, for example in order to drive the motor vehicle or to support the electrical machine in driving the motor vehicle. Also takes place at the block 28 for example, a time forecast as to when the internal combustion engine must be reactivated. In addition, for example, occurs at the block 28 a prediction of the power output with which the internal combustion engine must start again.

3 shows a further flow chart to further illustrate the method. A block 30th illustrates, for example, ADAS or GPS and / or a navigation device, which - as by a case 32 is illustrated - provides predictive route data in an electronic horizon. With a block 34 a signal processing takes place, which - as indicated by an arrow 36 illustrates - provides input attributes. In the case of a slope detection, the input attributes characterize at least one or more slopes, for example. In the case of city recognition, the input attributes characterize, for example, a city and / or at least one or more speed limits. In the case of target recognition, the input attributes characterize, for example, at least part of a calculated route which the motor vehicle is to travel on or is being traveled on. A block 38 illustrates a recognition algorithm which, for example, carries out an incline recognition, a city recognition and / or a target recognition. The block 28 provides output attributes, which are indicated by an arrow 40 are illustrated. The output attributes characterize at least one slope attribute, at least one city attribute and / or at least one destination attribute, for example. Finally, a block illustrates 42 a control, in particular a regulation or control, whereby the drive train and thus the internal combustion engine and / or the regeneration is operated, in particular controlled or regulated. An algorithm for slope detection receives as input variables, for example, a minimum for a positive gradient, a maximum for a negative gradient and the at least one slope. Outputs of the algorithm are, for example, a start of the slope, an end of the slope, a vector length as a control, a distance to the slope and a slope length. The algorithm for city recognition receives as input variables, for example, at least one speed limit, at least one value that characterizes a built-up area and / or navigation data that can characterize a current position of the motor vehicle. As outputs, the algorithm for city recognition provides, for example, a beginning of a city, an end of a city, a vector length as a control, a distance to the beginning of the city and / or a city length. The algorithm for target recognition receives, for example, a position of the motor vehicle along the calculated route and the current position of the motor vehicle as input variables. The target detection algorithm provides, for example, a vector length as a control and a distance to the target as the output variable. As a result, the route ahead can be determined particularly precisely, so that the time span can be predicted particularly precisely. As a result, the regeneration of the particle filter can advantageously be carried out so that when the internal combustion engine is restarted, particles can again be filtered out of the exhaust gas and at least temporarily stored by means of the particle filter. In this way, a particularly low-emission and energy-efficient operation of the motor vehicle can be guaranteed.

List of reference symbols

10

block

12th

block

14th

block

16

block

18th

block

19th

block

20th

block

21

block

22nd

block

24

block

26th

block

28

block

30th

block

32

arrow

34

block

36

arrow

38

block

40

arrow

42

block

QUOTES INCLUDED IN THE DESCRIPTION

This list of the documents listed by the applicant was generated automatically and is included solely for the better information of the reader. The list is not part of the German patent or utility model application. The DPMA assumes no liability for any errors or omissions.

Patent literature cited

• DE 102016014255 A1 [0002, 0011]
• DE 102016014254 A1 [0011]

Claims (7)

A method for operating an exhaust gas aftertreatment device of a motor vehicle through which exhaust gas from an internal combustion engine can flow and which has at least one particle filter, characterized in that, depending on at least one route of the motor vehicle ahead of the motor vehicle, a future period of time during which fired operation of the internal combustion engine will not take place is forecast, wherein a regeneration of the particulate filter is carried out at least during part of the period of time as a function of the predicted period of time. Procedure according to Claim 1 , characterized in that an end time at which the time span ends is also forecast, the regeneration of the particulate filter being carried out at least during part of the time span as a function of the predicted end time. Procedure according to Claim 1 or 2 , characterized in that power to be provided by the internal combustion engine at one end of the time period is also predicted, the regeneration of the particulate filter being carried out at least during part of the time period as a function of the predicted power. Method according to one of the preceding claims, characterized in that, for the regeneration of the particle filter, a fuel-air mixture is burned at least during part of the period by means of a burner which is different from the internal combustion engine and is additionally provided, whereby the particle filter is heated and thereby regenerated. Method according to one of the preceding claims, characterized in that at least during part of the period of time the particle filter is heated by means of a catalytic burner and is thereby regenerated. Method according to one of the preceding claims, characterized in that for the regeneration of the particle filter, at least during part of the period of time, a gas flow is generated which is at least the Particle filter flows through. Procedure according to Claim 6 in its reference to Claim 4 or 5 , characterized in that the gas stream is heated by means of the burner.

Images