DE102017221739A1 - Method for operating a drive device and corresponding drive device - Google Patents

Abstract

The invention relates to a method for operating a drive device which has an exhaust-producing internal combustion engine and a particle filter for filtering the exhaust gas of the internal combustion engine. It is provided that after a start of operation of the internal combustion engine and / or after regeneration of the particulate filter, a conditioning operation is performed, being conditioned during the conditioning operation of the particulate filter by targeted Rußpartikeleintrag and for conditioning the particulate filter, the internal combustion engine for generating soot particles with another Particle size distribution (d) and / or for producing a larger particulate mass and / or a larger soot particle number than during normal operation of the drive device is operated. The invention further relates to a drive device.

Description

The invention relates to a method for operating a drive device which has an exhaust-producing internal combustion engine and a particle filter for filtering the exhaust gas of the internal combustion engine. The invention further relates to a drive device.

From the prior art, for example, the publication DE 102 35 766 A1 known. This relates to an exhaust gas filter for cleaning an exhaust gas of an internal combustion engine, formed from at least one strip-shaped filter layer with at least one filter region of at least partially fluid-flow material and optionally a metal foil, wherein the filter layer at least one contact region with a catalytically active coating for the reaction of gaseous components of the exhaust gas and a filter region for filtering particles from the exhaust gas.

Furthermore, the document describes DE 10 2009 057 768 A1 a particle filter device for removing particles from the exhaust gas of a furnace, with at least one retaining device for mounting in an exhaust gas flow path of the furnace, such that the exhaust gas is flowed through the exhaust during operation of the furnace exhaust gas. Particles from the exhaust gas of a furnace can be removed better if the retainer has a plurality of retaining elements which are movable relative to each other and which are arranged in the assembled state of the retainer in the exhaust gas flow path, such that they are flowed around during operation of the furnace exhaust gas.

It is an object of the invention to propose a method for operating a drive device, which has advantages over known methods, in particular realizes a high filtering effect of the particulate filter without structural measures.

This is achieved according to the invention with a method for operating a drive device having the features of claim 1. It is provided that after a start of operation of the internal combustion engine and / or after regeneration of the particulate filter, a conditioning operation is performed, being conditioned during the conditioning operation of the particulate filter by targeted Rußpartikeleintrag and for conditioning the particulate filter, the internal combustion engine for generating soot particles with a different particle size distribution and / or for producing a larger particulate mass and / or a larger soot particle number than during normal operation of the drive device is operated.

The drive device is provided for example for use in a motor vehicle and in this case associated with the motor vehicle. The drive device serves to provide a drive torque. If the drive device is assigned to the motor vehicle, then it is provided and designed for driving the motor vehicle, in other words for providing the drive torque, which is directed to the driving of the motor vehicle. The drive device has to provide the drive torque via the internal combustion engine, which generates exhaust gas during its operation.

The internal combustion engine is present, for example, as an Otto internal combustion engine or as a diesel internal combustion engine. In any case, the internal combustion engine generates exhaust gas during its operation, which in turn contains soot particles. The exhaust gas or the soot particles formed during combustion of a fuel or fuel in the internal combustion engine. The soot particles are present in the exhaust gas produced by the internal combustion engine and are removed together with this. They arise in particular due to incomplete combustion of the fuel.

In order to at least partially remove the soot particles from the exhaust gas and thus to prevent the soot particles from being discharged into an external environment of the drive device, the particle filter is provided. This is fluidly downstream with respect to the exhaust gas of the internal combustion engine. In this respect, the exhaust gas produced by the internal combustion engine, preferably completely, is fed to the particle filter. The particulate filter at least partially filters the soot particles out of the exhaust so that the exhaust downstream of the particulate filter contains less soot than the exhaust upstream of the particulate filter.

The filtered-out soot particles remain in the particulate filter and increase over time. It is therefore necessary to regenerate the particulate filter from time to time. For this purpose, the temperature of the particulate filter or of the exhaust gas flowing through the particulate filter is usually increased in such a way that the soot particles burn. For this purpose, the particle filter can be provided with a catalytic coating which facilitates the burning or burning off of the soot particles, namely such that the burning takes place already at a lower temperature than without the coating.

During the regeneration of the particulate filter, that is to say when the soot particles burn, ash is produced which remains at least partially permanently in the particulate filter. On the one hand, it is therefore possible to load the particle filter with soot particles from a load of the particle filter with ash be differentiated. The former can also be referred to as soot loading and last as ash load. From the soot loading and the ash load results in the total load, for example, a sum of the two values. The loading or each of the loadings describes the amount of the respective substance in the particle filter. The soot loading is so far the amount of soot in the particulate filter and the ash load for the amount of ash.

The filtration performance of the particulate filter depends on various factors, namely in particular on its loading, for example on the soot load and / or the ash load and / or the total load. Particularly in the case of the Otto internal combustion engine, the filtration performance of the particulate filter increases with increasing loading, at least up to a certain upper limit, above all due to the small particle size of the soot particles produced by the Otto internal combustion engine. In addition, the regeneration, at least for the Otto internal combustion engine such that the soot loading is completely degraded so that it is equal to zero after regeneration or at least low.

After regeneration, essentially only the ash charge remains. This means that the filtration performance of the particulate filter after regeneration is lower than before and essentially determined by the ash charge. In any case, both for the Otto internal combustion engine and for the diesel internal combustion engine, the filtration performance of the particulate filter with completely unloaded particulate filter, so for example at a brand new particulate filter, particularly low.

For this reason, it is provided to carry out the conditioning operation after the start of operation of the internal combustion engine and / or after the regeneration of the particulate filter. During the conditioning operation, the filtration performance of the particulate filter is improved by selectively introducing soot particles into it. For this purpose, the drive device or the internal combustion engine is operated in the conditioning mode, that is, for example, switched from the normal mode to the conditioning mode. After the conditioning is again preferably switched from the conditioning mode to normal operation.

The normal operation of the drive device is to be understood as an operating mode in which the drive device is operated as fuel-efficient as possible and / or with the lowest possible pollutant emissions. For example, it is provided in the context of normal operation to adjust these so that during their operation the lowest possible particulate matter mass is present in the exhaust gas.

During the conditioning operation, the internal combustion engine is set such that it generates more soot particles, that is, in the exhaust gas, a larger particulate mass is contained than during normal operation. Additionally or alternatively, the soot particles should have a different particle size or a different particle size distribution than during normal operation. The particle size is to be understood as meaning the average size of the soot particles contained in the exhaust gas. For example, an equivalent diameter of the soot particles, in particular an average equivalent diameter, is used as the particle size. Particularly preferably, a geometric equivalent diameter is used, for example a volume-equivalent spherical diameter or a surface-equivalent spherical diameter. The particle size distribution gives the statistical distribution of the particle size for all soot particles, ie the frequency with which the soot particles have a certain particle size. In other words, the particle size distribution represents a frequency distribution for different particle sizes of the soot particles.

The larger the soot particles, the larger their particle size, the higher the filtration performance of the particulate filter, because it increases independently of the particle size loading. The larger the particle size of the soot particles, the more effectively the loading of the soot particle can be increased without undesired particles passing through the particle filter. For example, to condition the particle filter, the particle size distribution can be changed in the direction of larger particle sizes. For example, the larger particulate mass is caused solely by the increase in particle size, so that - statistically speaking or average - the number of soot particles in the exhaust during the conditioning operation corresponds to the number during normal operation or at least approximately.

Additionally or alternatively, however, it can also be provided that the number of soot particles contained in the exhaust gas is increased in the conditioning operation in comparison to the normal operation. This can be accompanied by the increase or decrease of the particle size. Thus, for example, the particle size distribution is changed in the direction of smaller particle sizes. However, it can also be provided that the particle size during the conditioning operation corresponds to the particle size during normal operation or at least approximately corresponds.

Finally, it is provided according to the invention to introduce targeted particles in the particulate filter in order to improve its filtration performance. Performing the conditioning operation is preferably provided when the loading of the particulate filter is low, for example, less than a loading threshold. It is preferably provided to carry out the conditioning operation after the start of operation of the internal combustion engine and / or after the regeneration of the particulate filter, for example, but only if the load is less than the loading threshold value. Under the start of operation of the internal combustion engine is a commissioning of the internal combustion engine to understand, which is accompanied by an activation of an ignition of the internal combustion engine and / or increasing the speed of the internal combustion engine from zero in the direction of an idle speed or the idle speed.

A further embodiment of the invention provides that for varying the particle size distribution and / or the particulate mass and / or the Rußpartikelanzahl the internal combustion engine is operated such that a combustion temperature is lower than during normal operation, and / or introduced into a combustion chamber fuel mass flow is greater as during normal operation, and / or incident on a combustion chamber boundary collision mass flow of the introduced into the combustion chamber fuel is greater than during normal operation. The lower the combustion temperature, the more soot particles accumulate during operation of the internal combustion engine, in particular because the soot particles are not combusted within the engine. In addition, the combustion proceeds with a lower efficiency than at higher combustion temperatures.

Additionally or alternatively, the fuel mass flow can be increased, which is introduced during operation of the internal combustion engine in the combustion chamber. In other words, the fuel-air mixture present in the combustion chamber is set fatter than during normal operation. Particularly preferably, the fuel mass flow is adjusted such that there is a lack of air in the combustion chamber, so that the introduced fuel can not be completely burned due to the lack of oxygen.

Additionally or alternatively, the introduction of the fuel is performed such that the collision mass flow is greater than during normal operation. The collision mass flow is the amount of fuel per unit time that impinges on the combustion chamber boundary. Under the Brennraumbegrenzung is any understanding of the combustion chamber device to understand. For example, the combustion chamber boundary is formed by a cylinder wall, a cylinder roof and a piston head together. Other elements present in the combustion chamber, for example a spark plug or the like, also form part of the combustion chamber boundary.

Meets fuel after its introduction to the combustion chamber boundary, namely in still liquid state, it is incomplete incinerated during operation of the internal combustion engine, so that the soot particle mass and / or the particle size increases. The measures mentioned can be carried out in a simple manner without additional structural measures. For example, to increase the collision mass flow, the fuel pressure is increased or the time of introduction of the fuel is changed. In other words, for example, the injection timing of the fuel is changed so that a wall wetting occurs more. During a homogeneous operation, this is done with injection in the vicinity of a charge change, in operation with multiple injection by shifting a final injection in the direction of an upper Zündtotpunkts (ignition TDC).

In the context of a further embodiment of the invention it can be provided that the conditioning operation is carried out before the normal operation. For example, it is provided to first carry out the conditioning operation after the start of operation of the internal combustion engine and then to go into normal operation. In other words, the conditioning operation switches directly to normal operation and accordingly the internal combustion engine is operated to produce soot particles having a smaller particle size and / or to produce a smaller soot particle mass than during the conditioning operation.

For example, it is provided to carry out the conditioning operation only once after each start of operation of the internal combustion engine or at least on the basis of the load to check whether the performing the conditioning operation is necessary and perform the conditioning operation, if this condition applies. Subsequently, the normal operation is performed so that there are no restrictions from changed operating parameters of the internal combustion engine for a driving operation of the motor vehicle. With such a procedure, no losses whatsoever are recorded during operation of the drive device.

A further preferred embodiment of the invention provides that the conditioning operation after a heating of the particulate filter and / or a catalytic converter of the Drive device serving heating operation is performed. The heating operation is used to heat the particulate filter or the exhaust gas catalyst, ie increasing the temperature in the direction or to a respective operating temperature. The operating temperature of the particulate filter and / or the operating temperature of the catalytic converter is to be understood in each case that temperature which is to be present during continuous normal operation. For example, an optimum filtration performance of the particulate filter or an optimum conversion performance of the catalytic converter is achieved at the operating temperature.

During operation of the internal combustion engine, that is to say also during the conditioning operation, this generates pollutants which are contained in the exhaust gas or are removed together with it. In order to prevent these pollutants from entering the external environment of the drive device during the conditioning operation, the particle filter or the catalytic converter should first be heated so that the filtration performance or the conversion efficiency increases. Already during the conditioning operation, a pollutant emission of the drive device is thus significantly reduced. The heating of the particulate filter is provided in particular when the exhaust gas catalytic converter is integrated in the particulate filter, for example in the form of a catalytic coating of the particulate filter.

A further embodiment of the invention provides that the combustion temperature during the conditioning operation is set lower than during the heating operation. First, the internal combustion engine is operated at a higher combustion temperature during the heating operation, which precedes the conditioning operation. By contrast, during the conditioning operation, the combustion temperature is reduced to increase the particle size and / or particulate mass. Subsequently, the combustion temperature can be set higher again during the normal operation following the conditioning operation than during the conditioning operation. To carry out the conditioning operation, the combustion temperature is temporarily lowered in this respect. This allows a particularly efficient and easy way to carry out the conditioning operation.

A further embodiment of the invention provides that the conditioning operation is started upon reaching a first catalyst threshold temperature by a catalyst temperature of the catalytic converter and / or after a certain delay period has elapsed after the start of operation of the internal combustion engine. The catalyst temperature is preferably measured by means of a temperature sensor. However, it can also be calculated by means of a model or otherwise estimated. For increasing the catalyst temperature, for example, the heating operation is performed. Once the catalytic converter or its catalyst temperature has reached the first catalyst threshold temperature, it can be assumed that its conversion capacity is sufficient to carry out a sufficient cleaning of the exhaust gas from the pollutants.

Additionally or alternatively, it may be provided to start or initiate the conditioning operation only after the expiry of the specific delay time. The delay period begins with the start of operation and has a certain length. It is preferably provided that both conditions must be fulfilled, ie both the delay time period must have expired and the catalyst temperature must have reached the catalyst threshold temperature. Both conditions can be implemented with simple means, in particular using already existing devices of the drive device, so that in particular no additional devices are necessary.

A preferred embodiment of the invention provides that the conditioning operation until reaching a second catalyst threshold temperature by the catalyst temperature and / or until reaching a motor threshold temperature by an engine temperature of the internal combustion engine and / or until the expiry of a certain conditioning period from the start of the conditioning operation and / or is performed until reaching a total loading threshold by a total load of the particulate filter and then terminated. The conditioning operation is performed until one or more of the above conditions are met. It may be sufficient here that exactly one of the conditions is fulfilled. Preferably, however, it is checked for the fulfillment of several or all of the conditions mentioned and the conditioning operation is only ended when these are fulfilled.

For example, it can be checked whether the catalyst temperature has reached or exceeded the second catalyst threshold temperature. The second catalyst threshold temperature is higher than the first catalyst threshold temperature. Additionally or alternatively, the engine temperature is compared with the engine threshold temperature. Only when the engine temperature has reached or exceeded the engine threshold temperature can the conditioning operation be terminated. The engine temperature is preferably measured by means of a temperature sensor. Also a provision of Engine temperature in other ways, for example by means of a model, may be provided.

The condition is particularly easy to implement that the conditioning operation is terminated only with the expiry of the specific conditioning period. The conditioning period begins with the start of the conditioning operation and has a certain length. Additionally or alternatively, the total load of the particulate filter may be determined and compared to the total load threshold. Only when the total load has reached or exceeded the total load threshold will the conditioning mode be terminated. Instead of total charge, soot load or ash load may also be used and compared with a soot loading threshold or ash loading threshold, respectively. By using the above conditions, it is ensured that after the conditioning operation of the particulate filter has a sufficient filtration performance. In addition, the conditions are easy to implement.

A particularly preferred further embodiment of the invention provides that the particle filter is regenerated upon reaching a first Rußbeladungsschwellenwerts by soot loading of the particulate filter by a regeneration operation is performed, in particular until reaching the total load threshold by the total load and / or to below a second Rußbeladungsschwellenwerts through the soot loading. The soot loading of the particulate filter is measured, for example, determined in particular by means of a differential pressure measurement. Alternatively, the soot loading can also be determined in other ways, for example by means of a corresponding model.

When the soot charge reaches or exceeds the first soot loading threshold, it is necessary to perform the regeneration operation during which the soot particles present in the particulate filter are burned and at least partially converted to ash. In other words, the particulate filter is regenerated during the regeneration operation and reduces its soot loading. Performing the regeneration operation is provided, for example, when the total load of the particulate filter reaches or exceeds the total load threshold.

In this case, provision may be made for the conditioning operation initially to be carried out until the total charge of the particle filter reaches or exceeds the total charge threshold value. Immediately thereafter, the regeneration operation is performed, in which the total load of the particulate filter is reduced again. However, because the soot particles present in the soot particle are converted to ash, a higher filtration efficiency remains after the regeneration operation than before the conditioning operation.

Alternatively or additionally, it may be provided that the regeneration operation is carried out until the soot load reaches or falls below the second soot loading threshold value. The second soot loading threshold is less than the first soot loading threshold, so reducing soot loading is achieved in the regeneration mode. This procedure has the advantage that always a sufficient filtration performance of the particulate filter is realized.

Finally, it can be provided within the scope of a preferred further embodiment of the invention that the conditioning period is determined as a function of the total load and / or the soot load and / or age of the particulate filter. The conditioning period is preferably the period over which the conditioning operation is performed at least. Before the end of the conditioning period, the conditioning mode is not terminated in this respect. The conditioning period may be selected depending on at least one of the following parameters: total load, soot load and age of the particulate filter.

For example, the higher the total load and / or the soot load, the shorter the conditioning period. Here, the total load is preferably weighted higher than the soot loading. Conversely, the higher the age of the particulate filter, the shorter the conditioning period, because with increasing age usually the total load increases due to the ash remaining in the particulate filter. Setting the conditioning period based on the explained parameters is particularly easy to implement and requires no additional facilities.

The invention further relates to a drive device, in particular for carrying out the method according to the statements in the context of this description, which has an exhaust-producing internal combustion engine and a particle filter for filtering the exhaust gas of the internal combustion engine. It is provided that the drive device is adapted to carry out a conditioning operation after a start of operation of the internal combustion engine and / or after regeneration of the particulate filter, wherein during the conditioning operation of the particulate filter is conditioned by targeted soot particulate entry and for conditioning of the particulate filter, the internal combustion engine Generating soot particles with a different particle size distribution and / or for generating a larger particulate mass and / or a larger soot particle number than during normal operation of the drive device is operated.

The advantages of such an approach or such an embodiment of the drive device has already been pointed out. Both the drive device and the method for its operation can be further developed according to the statements in the context of this description, so that reference is made to this extent.

• 1 ein Diagramm, in welchem eine Katalysatortemperatur und eine Motortemperatur sowie Filtrationsleistungen eines Partikelfilters einer Antriebseinrichtung über der Zeit aufgetragen sind, sowie
• 2 ein Diagramm, in welchem zwei Häufigkeitsverteilungen über einer Partikelgröße für unterschiedliche Betriebsarten der Antriebseinrichtung aufgetragen sind.

The invention will be explained in more detail with reference to the embodiments illustrated in the drawings, without any limitation of the invention. Showing:

• 1 a diagram in which a catalyst temperature and an engine temperature and filtration performance of a particulate filter of a drive device are plotted over time, and
• 2 a diagram in which two frequency distributions are plotted over a particle size for different operating modes of the drive device.

The 1 shows a diagram in which a course 1 an engine temperature of an internal combustion engine of a drive device over the time t is plotted. Furthermore, in the diagram is a course 2 a catalyst temperature of an exhaust gas catalyst of the drive device applied, wherein the exhaust gas catalyst is used to purify exhaust gas, which is generated by the internal combustion engine during its operation. Finally, gradients show 3 and 4 the filtration efficiency η of a particulate filter which serves to filter the exhaust gas of the internal combustion engine.

It is preferably provided to supply the exhaust gas of the internal combustion engine completely to both the exhaust gas catalytic converter and the particulate filter and subsequently, ie after the flow through both the exhaust gas catalytic converter and the particulate filter through the exhaust gas, to an external environment of the drive device. The history 3 shows the filtration efficiency η of the particulate filter for a conventional method for operating the drive device.

The history 4 on the other hand shows the filtration efficiency η for an improved operating method of the drive device. In its scope, it is provided that after a start of operation of the internal combustion engine and / or after a regeneration of the particulate filter, a conditioning operation is performed. The conditioning operation serves to improve the filtration efficiency η or filtration performance of the particulate filter by selectively introducing soot particles into it.

For conditioning the particulate filter, it is provided to operate the internal combustion engine during the conditioning operation for producing soot particles having a different particle size or a different particle size distribution and / or for producing a larger particulate mass and / or soot particle number than during normal operation of the drive device. The start of operation of the internal combustion engine takes place in the embodiment shown here in the time t ₀ , Subsequently, a heating operation, during which the internal combustion engine is operated for rapid heating of the catalytic converter. In the embodiment shown here, the heating operation is up to the time t ₁ performed and then immediately switched to the conditioning mode for conditioning the particulate filter.

It is clear that at the time t ₁ the catalyst temperature of the catalytic converter is already almost at its operating temperature ts has reached. The conditioning operation will be until the time t ₂ carried out. It can be clearly seen that conditioning of the particulate filter during the conditioning operation results in its filtration performance in accordance with the course 4 increases significantly faster than when performing a normal operating method, in which the normal operation is immediately followed by the heating operation. The normal operation is for the embodiment shown here from the time t ₂ carried out.

The 2 shows a diagram in which gradients 5 and 6 show two different particle size distributions, wherein the particle size distribution describes the frequency q over the particle size in the form of the equivalent diameter d of the soot particles. The internal combustion engine is now operated such that during normal operation of the course 5 whereas, during the conditioning operation to condition the particulate filter, the course 6 is present. It becomes clear that the course 6 has its maximum at a larger particle size than the course 5 , By operating the internal combustion engine such that the average particle size during the conditioning operation is different, in particular greater, than during normal operation, the filtration performance of the particulate filter is rapidly increased.

Overall, the method described for operating the drive device allows a rapid increase in the filtration performance of the particulate filter. This is possible without additional facilities. Rather, the method can be applied to existing drive devices readily.

QUOTES INCLUDE IN THE DESCRIPTION

This list of the documents listed by the applicant has been 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.

Cited patent literature

• DE 10235766 A1 [0002]
• DE 102009057768 A1 [0003]

Claims (10)

Method for operating a drive device, which has an exhaust-producing internal combustion engine and a particulate filter for filtering the exhaust gas of the internal combustion engine, characterized in that after a start of operation of the internal combustion engine and / or after regeneration of the particulate filter, a conditioning operation is performed, wherein during the conditioning operation of the particulate filter is conditioned by targeted soot particulate entry and for conditioning of the particulate filter, the internal combustion engine is operated to produce soot particles with a different particle size distribution (d) and / or to produce a larger particulate mass and / or a larger soot particle number than during normal operation of the drive means. Method according to Claim 1 , characterized in that for varying the particle size distribution and / or the soot particle mass and / or the Rußpartikelanzahl the internal combustion engine is operated such that - a combustion temperature is lower than during normal operation, and / or - a fuel mass flow introduced into a combustion chamber is greater than during of the normal operation, and / or - an incident on a combustion chamber boundary collision mass flow of the introduced into the combustion chamber fuel is greater than during normal operation. Method according to one of the preceding claims, characterized in that the conditioning operation is carried out before the normal operation. Method according to one of the preceding claims, characterized in that the conditioning operation is performed according to a heating operation serving for heating the particulate filter and / or an exhaust gas catalytic converter of the drive device. Method according to one of the preceding claims, characterized in that the combustion temperature during the conditioning operation is set lower than during the heating operation. Method according to one of the preceding claims, characterized in that the conditioning operation is started upon reaching a first catalyst threshold temperature by a catalyst temperature (t) of the catalytic converter and / or after a certain delay period from the start of operation of the internal combustion engine. Method according to one of the preceding claims, characterized in that the conditioning operation until reaching a second catalyst threshold temperature by the catalyst temperature (t) and / or until reaching a motor threshold temperature by an engine temperature (T) of the internal combustion engine and / or until the expiry of a certain conditioning period is performed from the start of the conditioning operation and / or until reaching a total loading threshold by a total load of the particulate filter and then terminated. Method according to one of the preceding claims, characterized in that the particle filter is regenerated upon reaching a first Rußbeladungsschwellenwerts by soot loading of the particulate filter by a regeneration operation is performed, in particular until reaching the total load threshold by the total load and / or to below a second Rußbeladungsschwellenwerts through the soot loading. Method according to one of the preceding claims, characterized in that the conditioning period as a function of the total load and / or the soot load and / or an age of the particulate filter is determined. Drive device, in particular for carrying out the method according to one or more of the preceding claims, comprising an exhaust gas generating internal combustion engine and a particulate filter for filtering the exhaust gas of the internal combustion engine, characterized in that the drive device is adapted to after an operating start of the internal combustion engine and / or after regeneration of the particulate filter to carry out a conditioning operation, wherein during the conditioning operation of the particulate filter is conditioned by targeted Rußpartikeleintrag and for conditioning the particulate filter, the internal combustion engine for producing soot particles with a different particle size distribution (d) and / or to produce a larger particulate mass and / or a larger Soot particle number is operated as during normal operation of the drive device.

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