WO2015169958A1

WO2015169958A1 - Method and device for regeneration of a particle filter

Info

Publication number: WO2015169958A1
Application number: PCT/EP2015/060223
Authority: WO
Inventors: Mark Hendrikx
Original assignee: Fev Gmbh
Priority date: 2014-05-09
Filing date: 2015-05-08
Publication date: 2015-11-12
Also published as: DE102014006692A1; DE112015002182A5

Abstract

The invention relates to a method implemented in an engine controller of a vehicle, wherein the method performs a particle filter regeneration for an internal combustion engine of the vehicle operating in accordance with the Otto principle, wherein the particle filter regeneration follows a multi-stage regeneration strategy, wherein after a first stage, in which a passive regeneration strategy can be performed, at least the following steps can be performed: determining a soot content in a particle filter of an exhaust gas system of the internal combustion engine, checking if the soot content exceeds a specified maximum value, performing a first active regeneration strategy if the specified maximum value is exceeded, wherein the active regeneration strategy demands intervention in an operating strategy of the vehicle, examining if the success of the first active regeneration strategy is sufficient, performing at least one second active regeneration strategy if the success of the first active regeneration strategy is insufficient.

Description

METHOD AND DEVICE FOR REGENERATING A PARTICLE FILTER

The present invention relates to a method implemented in an engine control of a vehicle, in particular a landbound, ^{vorzugswei ¬} se road and / or off-road vehicle, the method is a particulate filter regeneration in a working on a gasoline principle, preferably direct injection and or injector-injecting internal combustion engine of the vehicle, wherein the particulate filter regeneration pursues a multi-stage regeneration strategy. Furthermore, a vehicle is proposed which has implemented such a method.

Different strategies emerge from the state of the art, as could be taken into account in a road vehicle, the ever stricter exhaust gas regulations in engines operated according to the Otto principle. Essentially, solutions are used for this, which relate to the otto engine combustion, on the one hand, and the exhaust gases and their catalytic post-processing, on the other hand. For example, DE 10 2006 021 302 B3 describes a method for determining a soot concentration in an exhaust gas of a direct injection internal combustion engine. The amount of soot in the exhaust gas is determined by means of a calculation model. For this purpose maps are ver ^{¬ used} , which are generated in a stationary state on the engine test bench and a soot emissions depending on an operating condition of the internal combustion engine in the test bench reproduces. The method takes into account that the soot emission and the nitrogen oxide emission of a directly injecting internal combustion engine correlate with each other and the nitrogen oxide emission in the exhaust gas can be detected by means of a sensor by measurement. ^¬ out from the measured nitrogen oxide concentration is to be closed with the addition of appropriate markings on the soot concentration in the exhaust ^¬ to. The method takes into account a passive as well as an active regeneration of the particulate filter used. An active regeneration can be effected by an auxiliary burner or by a post-injection of additional fuel into the combustion chamber. By doing so, a trade-off to an internal combustion engine is to be avoided. DE 10 2011 107 692 B3, in turn, describes a method for reactivating exhaust gas purification systems for lean-burn engines comprising an oxidation catalyst and a particle filter. There should be a reactivation of the particulate filter during a fuel cut of the engine.

The DE 10 2010 044 102 AI, however, describes another exhaust system for an internal combustion engine, which is provided with a particulate filter. The exhaust system comprises a catalyst and this downstream of the particulate filter. Furthermore, a secondary air inlet opening for introducing secondary air via at least one flutter valve in the exhaust line is provided in the exhaust line upstream of the particulate filter. The document states that strict direct emissions emission limit values must be observed for gasoline engines with direct injection. Through the secondary inlet opening, the introduction of secondary air via the flutter valve and thus the introduction of additional oxygen for the oxidation or combustion of soot particles in the particulate filter is possible. Thus, it should not be necessary to supply secondary air to the combustion chamber of the internal combustion engine, in order to increase a portion of the unburned residual oxygen in the exhaust gas for the regeneration of the particulate filter. The exhaust system can be used with internal combustion engines, which have a fuel cut.

The object of the present invention is to be able to design a combustion engine operating according to the Otto principle for the future in terms of emission standards to be complied with.

This object is achieved by a method having the features of claim 1 and by a vehicle having the features of claim 13. Further advantageous embodiments and further developments will become apparent from the following subclaims. However, one or more features of one or more different embodiments as well as subclaims may also be linked to further embodiments. The respective inde ^¬ Gigen claims and their characteristics are, moreover, a first formulation of the subject invention. Therefore, one or more features may as well additionally added, exchanged and / or features of the independent claims are deleted to describe the subject invention.

According to the present invention, there is provided a method implemented in an engine control system of a vehicle, the method performing a particulate filter regeneration on an Otto-type internal combustion engine of the vehicle, the particulate filter regeneration following a multi-stage regeneration strategy in which after a first Stage at which a passive regeneration strategy is executable, at least the following steps are executable:

Determining a soot content in a particulate filter of an exhaust line of the internal combustion engine,

- check whether the soot content exceeds a specified maximum value,

Performing a first active regeneration strategy when the predetermined maximum value is exceeded, wherein the active regeneration strategy involves an intervention in an operating strategy of the vehicle,

Check that the success of the first active regeneration strategy is sufficient

Execute at least one second active regeneration strategy if the success of the first active regeneration strategy is insufficient.

Further, a method is proposed implemented in an engine control of a vehicle, wherein the method performs a particulate filter regeneration in a working on a Otto principle, preferably direct injection and / or an intake manifold internal combustion engine of the road vehicle, wherein the particulate filter regeneration pursues a multi-stage regeneration strategy comprising at least the following steps:

Determining a soot content in a particulate filter of an exhaust line of the internal combustion engine, - checking based on at least three different regeneration Strate ^¬ technologies, each require a different procedure in an operating strategy of the road vehicle, which is this regeneration strategies are being used, being in this case at least inspected passive regeneration strategy and optionally applied, and

Regenerating the particulate filter by means of the selected regeneration strategy.

Preferably, the proposed method is used in the context of an engine control for a special operation of the particulate filter regeneration in the internal combustion engine. Thus, the proposed method is particularly suitable for preventing a breakthrough or a blockage, provided that the predominant area of heating of the exhaust gas line by the exhaust gas temperatures in an internal combustion engine operated by the gasoline method is insufficient, sufficient particle combustion in the particle filter by means of the passive regeneration strategy in order to reduce or avoid clogging (and / or exceeding the maximum permissible load) thereof. Although the use of deceleration phases is optionally provided in this passive regeneration, in which an injection is turned off and thus sufficient oxygen in the particulate filter is present to carry out the combustion. ^¬ all recently presupposes that that indeed a sufficient temperature in the particulate filter to ignite present. If the internal combustion engine and the vehicle, however, only in a short operation in the city be moved ^¬ as due to the ever increasing urbanization, this is now the case, the probability shifts to the disadvantage of a passive regeneration strategy that this is sufficient for all possibilities ensuring the flowability of the particulate filter. Taking this into account, it has now been found that it is not sufficient to be able to achieve a sufficient guarantee of particle filter cleaning with a single, specific active regeneration strategy, in fact, for a wide variety of worst-case scenarios. Rather, it has surprisingly been found that at least three different penalties technologies are combined with one another only in a position to actually make that future security available for a variety of cases to Kings ^¬ nen that allows that also according to the Otto principle-driven internal combustion engine having a particulate filter, safe in all operating areas different circumstances can be used.

In particular, it has surprisingly been found that for vehicles with automatic transmission using such a graded operating strategy brings additional benefits, since depending on the selected operation of the transmission thereby also another active regeneration strategy can be used. Thus, for example, a vehicle is proposed which has an automatic transmission, wherein the automatic transmission has different operating modes adjustable, wherein each mode of operation is assigned a mutually different regeneration strategy. A further embodiment provides for a vehicle that at least one of the active regeneration strategies is linked to a limitation of a transient operating behavior of the internal combustion engine. Furthermore, it can be provided that the vehicle has the method implemented in such a way that at least each active regeneration strategy has a differently strong effect on an operating behavior of the internal combustion engine.

According to the present invention, after the second active regeneration strategy has been carried out, the success of the second active regeneration strategy can again be checked, and if at least one further third regeneration strategy can not be successful.

Furthermore, in the first active regeneration strategy, the operating strategy of the vehicle can be intervened in such a way that the probability of entering a fuel cut-off phase with hot exhaust gas temperatures is increased. In the first active regeneration ^strategy , the switch-on conditions of the fuel cut-off can be adapted, wherein a lower speed threshold is preferably selected.

In the first active regeneration strategy, certain transmission strategies can not be allowed.

The second active regeneration strategy may have a higher regeneration efficiency than the first active regeneration strategy, wherein the second active regeneration strategy has a greater influence on the driveability of the vehicle than the first active regeneration strategy.

The third active regeneration strategy can have a higher regeneration efficiency than the second active regeneration strategy, wherein the third active regeneration strategy has a greater influence on the driveability of the vehicle than the second active regeneration strategy.

In the second active regeneration strategy, the internal combustion engine may be operated at a low part load in a lean operation with a spark retard setting to increase an exhaust gas temperature.

In the third active regeneration strategy, fuel cutoff is provided to at least at least a single cylinder of the internal combustion engine at a low partial load point.

According to an advantageous embodiment, provision is made for a passive regeneration strategy to be checked first before one of the other regeneration strategies according to the above procedure is checked and if necessary applied. The particle filter loading of the soot particle filter can be determined, for example, via a differential pressure measurement via the soot particle filter. Additionally as well as alternatively, however, a soot loading level can also be predicted by means of a soot loading model, an evaluation of existing driving data or ambient data, or the soot particle filter loading can be estimated in another way. the . From the above-mentioned prior art, also different methods and devices emerge, with which the soot particle filter loading is detected. This is also referred to. For example, the soot load can be determined by detecting one or more of the following data: For example, a route and its geological profile, prevailing traffic conditions, especially traffic news, measured traffic speeds, information sent by vehicles in the immediate vicinity, climatic conditions such as temperature and humidity along the route, set driving profiles, for example, with regard to the stored in the control unit driving profiles, the desired procedure of switching in an automatic transmission as well as other suitable measures.

A further embodiment provides that a passive and active two Rege ^¬ nerationsstrategien successively or be tested in parallel, wherein at least one of the regeneration strategies is selected and executed, its success is checked and executed one of the other regeneration strategies with insufficient success, and again on the success is checked, which may be followed by at least one further regeneration. In particular, depending on a detected state, a repetition of at least one regeneration strategy, preferably of at least two active regeneration strategies, can take place. A success of a regeneration is preferably predeterminable. This success can be checked according to an embodiment, for example, based on at least one, in particular two parameters. This value may be, for example, a pressure drop across the particulate filter, a parameter taken downstream of the particulate filter, a particulate filter load, some other measurable particulate filter behavior due to soot loading, or others.

Preferably, the method provides that, when checking the at least four regeneration strategies, the following is checked:

- (a) checking that passive particulate filter regeneration is sufficient, (b) checking whether a first active regeneration strategy including a fuel cut-off phase with occurring hot exhaust gas is sufficient,

(c) checking whether a second active regeneration strategy including operating the internal combustion engine at a low partial load in a lean operation with setting a spark retard to increase an exhaust gas temperature is sufficient,

- (d) Checking whether a third active regeneration strategy including switching off fuel injection in at least individual cylinders of the internal combustion engine is sufficient in a low partial load point.

Furthermore, it is preferred that the method checks the steps (a) to (d) in this order and then optionally carried out individually.

A further embodiment of the method provides that the method performs steps (a) to (d) at least partially simultaneously.

When checking whether the respective selected or selectable regeneration strategy is sufficient, it is preferably checked to what extent sufficient regeneration can actually be produced in one of the at least three, preferably four regeneration strategies. For this purpose, according to one embodiment, for example, it is provided that the filter load is detected and, on the other hand, it is checked via a combustion model, for example, because the determined filter load can actually be sufficiently burned off by means of the respective regeneration strategy. According to one embodiment, it is provided that the same model for estimating the filter particle load is repeatedly accessed during a respective test. A further embodiment provides that the same function is also used for clarifying whether the respective regeneration strategy provides sufficient burn-up, for example a burn-off model. A further embodiment, in turn, provides that, depending on the regeneration strategy to be tested, a specific function or a specific model is selected with which the success of the respective regeneration strategy on the soot filter loading is determined, in particular estimated. In turn According to one embodiment, it is provided that also for the determination of the soot filter loading different options are available. It may be necessary to make use of different investigations during the examination. This may be dependent, for example, on whether a short-term or long-term test takes place. In this way, for example, there is the possibility that by means of a more complex check of the particle filter loading, for example, deviations in other measurement methods or model calculations, such as aging, other deposits as well as effects such as a permanent deposition of soot particles in a direct injection and / or with an internal combustion engine provided with a suction pipe injection can stop the Otto operation, be collected.

A further development of the method comprises that when determining the soot content estimation by means of a Rußentstehungsmodells occurs wel ^¬ ches at least taken into account of the following factors, preferably at least the following factors into consideration: an oil consumption, a soot emissions as a function of a rotational speed and / or load , one or more correction factors which are determined as a function of an implemented wall-film model of an Otto engine combustion, and one or more environmental conditions.

Moreover, it has proven to be advantageous if the method can access a permanent as well as a volatile memory. While the respective regeneration strategies are stored in the permanent memory, the access to a volatile memory enables the results of the respective tests, adjusted target values, results and model calculations as well as estimates for the specific time to be stored, but can be continuously adjusted or updated also override.

Furthermore, it is preferable if the method uses a combustion model in determining the soot content, which is based on an existing combustion Oxygen content, an exhaust gas mass flow and a filter temperature makes a quantitative estimate of a particulate filter regeneration.

In particular, the method can provide that a number of particles is determined, with regeneration of the particulate filter preferably being triggered when a predefinable maximum value is exceeded.

An exemplary embodiment of the method provides that the respectively active regeneration strategy be tested step by step in an order with increasing efficiency of the available regeneration strategies, but also with increasing influence on the driveability of the vehicle. If it turns out, for example, that the passive particulate filter regeneration strategy is not sufficient, the active regeneration strategy which has the least influence on the drivability of the vehicle is first checked. Under the influence on the drivability is in particular any specification regarding the provision of a fuel injection or its suppression to understand, especially taking into account the current driving operation. For example, increasing the influence over, for example, the engine control unit may result in a first active regeneration strategy attempting to increase a likelihood of obtaining a fuel cut-off phase with hot exhaust gas temperatures in the operator selected operating mode. For this purpose, for example, an adaptation of switch-on of the fuel cut-off can be made, for example by means of a lower speed threshold. It may also be provided, for example, that one or more transmission strategies are not permitted, for example as would otherwise be possible by means of a sailing (engine disengaged and idling). Such a strategy would probably be noticed by the user of the road vehicle only very little, but could already be sufficient for a variety of passive particle filter regeneration still insufficient cleaning present cases.

For example, another stage provides that, after some time, the previous level does not match the previous active regeneration strategy one, for example, by an adjustable default verifiable success has led to the particle filter cleaning is activated. In this case, it can be provided, for example, that the internal combustion engine is now operated lean at a low partial load, that is to say with a λ> 1. This is preferably carried out in conjunction with a spark retard. In this case, for example, an adjustment of the ignition can be made late. This is used in particular to increase the exhaust gas temperature. However, such a solution may also depend on a certain time frame within which this further active regeneration strategy must be performed. This may be due, for example, to the fact that the chosen strategy has a certain inertia. If the user-desired driving behavior now leads to the fact that this second, active regeneration strategy does not need to be tracked but interrupted or interrupted, it can lead to insufficient cleaning (or emptying) of the particulate filter due to burnup. Therefore, in such a situation, for example, it may be possible to use the third, active regeneration strategy. According to one embodiment, it is provided, for example, that an abort criterion is stored, from which the first, (and / or) second regeneration strategy is interrupted and then switched to the third, active regeneration strategy. In this case, according to an embodiment, it can be provided, for example, that an injection to individual cylinders of the internal combustion engine is switched off at low partial load points. Characterized oxygen is pushed into the exhaust gas through this cylinder, thereby creating the possibility to obtain an increased combustion temperature and hence a Besse ^¬ res burning of the particulates contained in the particulate filter. The ^¬ ses can be supported by, for example, that an ignition retarded or even a spark ignition as such, in turn, in turn, to increase the exhaust gas temperature in addition.

With spark retardation is meant an adjustment of the ignition timing, which leads to the fuel-air mixture in the cylinders being ignited after a thermodynamically optimal ignition time. As a result, the spark ignition has the consequence that an expansion of the burned power Substance air mixture is lower than in an ignition with thermodynamically optimal ignition angle, whereby the temperature of the expelled from the cylinder exhaust gas is increased.

If, for example, this fourth regeneration strategy should not be sufficient in its active form, provision can be made, for example, for additional activation to go beyond that. In particular, however, it is likewise provided that, if the result of the particle filter cleaning that is to be achieved is not achieved, finally a signal can be generated, which finally can lead to a warning function to the user of the internal combustion engine. In particular, an error message can also be made about this, which converts the internal combustion engine into a specific operating mode which is intended to prevent damage to components of the internal combustion engine by insufficient particle filter cleaning. For example, it can be provided that this restriction by the engine control unit becomes more drastic the longer the user of the vehicle ignores an optionally issued warning, for example displayed in a display of the road vehicle. This should in particular be prevented that a state is reached in which it comes to destruction of components of the internal combustion engine and the downstream exhaust system. Also, such a protection can be provided, for example, to prevent too high a combustion temperature by an excessive addition of unburned fuel to ver ^¬ which can otherwise lead to damage to not only the particulate filter but, if necessary surrounding of the particulate components of the vehicle.

According to a further aspect of the invention, which can be used independently as well as in connection with the proposed method, a vehicle, in particular a road vehicle and / or an off-road vehicle with an internal combustion engine operating according to the Otto principle, preferably with direct injection and / or intake manifold injection with an exhaust line, in which a particulate filter is arranged, proposed with an engine control unit, wherein the engine control unit a volatile and a nonvolatile memory having an implemented method for particle filter generation, preferably with a method as described above or as described in more detail below, wherein at least one passive particulate filter regeneration strategy is executable and at least two different active particulate filter regeneration strategies are implemented in the method, respectively take a different influence by means of the engine control unit on the operation of the internal combustion engine, and with an implemented determination of a loading state of the particulate filter, which is preferably implemented in the engine control unit.

Furthermore, it is preferable for the road vehicle to provide, in addition to the engine control unit, at least one further control device which is used in the particle filter regeneration. In addition to the possibility to allow in this way an at least partial redundancy, in particular a control option by independent counter-calculation, there is above all the possibility of being able to divide arithmetic operations. If, for example, the engine control unit is occupied with other additional tasks, the other control device can, for example, take over operations that the engine control unit otherwise performs.

Another embodiment provides that the engine control unit and / or at least one control unit connected to it operate as a parallel computer network. As a result, a computing capacity can be increased and, in particular even in a transient driving operation, accurate monitoring of the regeneration can be ensured.

A development provides that at least each active regeneration strategy has a different impact on a performance of the internal combustion engine. Furthermore, it can be provided that at least one of the active regeneration strategies is linked to a limitation of a transient operating behavior of the internal combustion engine. A further development provides that the vehicle has an automatic transmission, wherein the automatic transmission different operating has adjustable, further each mode of operation is assigned a mutually different regeneration strategy.

Furthermore, the proposed invention can be used not only in land vehicles such as road vehicles or off-road vehicles such as terrain ^¬ vehicles, tracked vehicles, construction vehicles or snowmobiles. Other vehicles such as marine vessels or Luftfahrzeu ^¬ ge can have at least the method implemented. Likewise, the method can also be used in internal combustion engines, which are integrated in work machines, in stationary as well as in mobile systems.

Under an operating according to the Otto principle internal combustion engine, a heat engine is understood, which initiate the combustion of a fuel-air mixture by means of spark ignition, such as a spark plug or a glow plug. As can be readily appreciated, both gasoline and petrol fuels as well as alternative fuels such as gaseous hydrocarbons (LPG, CNG) or hydrogen can be used. In addition, it is also possible to use ignition jet engines which ignite a homogeneous fuel / air mixture by means of an inhomogeneous ignition jet (direct diesel injection). In addition, internal combustion engines operating under the Otto principle can be operated both with a homogeneous and with an inhomogeneous fuel / air mixture, such as, for example, in direct gasoline injection.

Further advantageous embodiments and developments will become apparent from the following figures. However, the details that can be seen in the figures are not limited to the individual embodiments. Rather, one or more features of one or more figures may be linked to other features of other embodiments of the figures as well as the above description to further developments. In particular, the respective figures and illustrated embodiments are to be interpreted in an explanatory manner and are intended to indicate one of various possibilities for implementing the invention. It show below: 1 shows a detail of a vehicle, preferably a road vehicle with a working according to the Otto principle internal combustion engine with direct injection and arranged in an exhaust line particulate filter together with associated engine control unit and implemented there method according to the invention,

Fig. 2 shows a first exemplary embodiment of the proposed method, and

3 shows a second embodiment of the proposed method.

Fig. 1 shows a section of a road vehicle 1 with a working according to the Otto principle internal combustion engine 2 with direct injection. The internal combustion engine 2 has, for example, a first supply 3 via which air or an air / exhaust gas mixture is supplied. A second feed 4 is provided, for example, for the fuel (or fuel) to be directly injected. A first exhaust 5 is associated with an exhaust line 6. The first discharge 5 leads to a particle filter 7. From this, the exhaust gas finally flows through a second discharge 8 into the environment. The particulate filter 7 has, for example, a first sensor 9. Just as well as before and after the particulate filter 7, a second sensor 10 may be provided. The two sensors 9, 10 are connected to an engine control unit 11, in which the proposed method is implemented. Thus, a particulate filter loading can be determined. The method 12 is indicated here. The engine control unit 11 may be connected to a second control unit 13. The second control unit 13 can redundantly take over tasks for the engine control unit 11 as well as for the engine control unit 11. The engine control unit 11 in turn executes the method 12 and acts for this purpose on the internal combustion engine 2 as well as possibly also on other not ^¬ maneuverable components accordingly. Subsequently variety of ways at ^¬ possibilities for the design of the proposed method 12 will be explained in greater detail. Fig. 2 shows a first embodiment of a proposed method. At the beginning of operation of the vehicle by commissioning, for example, the internal combustion engine, a first test is initiated, indicated by the start 14. From start 14, there is a first query 15, which has the content, whether a soot content in a particulate filter of an exhaust system of the internal combustion engine is not too high, therefore, whether the previous particle filter cleaning was sufficient or whether a particle filter cleaning has to start soon. Thus, for example, it can be checked in this first query 15 whether, for example, a passive regeneration should first be performed, for example. It is also possible to check whether passive regeneration was sufficient. If this is the case in each case, the system returns to the start position with the number 14. On the other hand, if a passive regeneration strategy does not allow sufficient particle filter regeneration, or if it becomes apparent that the available memory option is so limited that passive regeneration is unlikely is sufficient, for example because too slow, can thus be moved to a next step 16. In this step 16, for example, a first active regeneration strategy is carried out, for example initiated a fuel cut, in which the hot exhaust gases occurring are passed directly into the particulate filter. It is therefore checked whether this particle filter regeneration was sufficient. If this is not the case, it can be decided, for example in this second query 17, to apply a second active regeneration strategy, as it is carried out in step 18. There is also the possibility, if the first, active regeneration is not enough to be able to repeat it. If, however, this first, active regeneration again leads to success, so that the particulate filter again allows sufficient filtration can be aborted and, for example, after some time or, for example, if a calculation of a soot content of the particulate filter indicates again with the step 14 and the following steps will be started. If the second, active regeneration strategy leads to success, it can then be aborted. If, for example, it does not lead to success, it can be repeated or, for example, another third, active regeneration strategy can be initiated. For example, while the second, active regeneration strategy For example, to provide for operation of the internal combustion engine at a low part load in a lean operation with setting spark retard to increase exhaust temperature, the third active regeneration strategy may include, for example, providing fuel injection shutdown at at least individual cylinders of the internal combustion engines to a low partial load point. Thus, after each regeneration strategy, a check of the result is preferably associated with regard to the possible further filtration capability of the particle filter. Furthermore, there is also the possibility that the various active regeneration strategies will be run through and only then will it be checked whether this has actually led to success, before a selection of one or more of the different regeneration strategies is initiated again. Such a cascade-like sequence thus has the possibility of ensuring, in particular even in the case of unsuccessful, that is, in particular incomplete, burning of the filtered soot particle filters via corresponding follow-up measures that, for example, no damage to a component of the internal combustion engine occurs, in particular it does not lead to uncontrolled combustion of Soot particles in the soot particle filter and thus thermal damage occurs. It can also be provided on the cascade-shaped design of the method that an error message goes to the engine control at the appropriate place and finally worn by engaging them in the operating strategy of the internal combustion engine possibly otherwise possible damage caused by locking of driving or load areas such as maximum load or the like and can be avoided.

FIG. 3 shows a further exemplary embodiment of a possible sequence of the proposed method. For example, it can be determined in a first step 20 whether the particulate filter functions at all or how its loading state is currently. In a subsequent step 21, a check can then be made as to whether, on the basis of, for example, predefinable parameters, the determined particle filter load makes it necessary to initiate a regeneration. If this is the case, for example, within the scope of step 21, it is also possible to directly which of the different possibilities of regeneration strategies are used at all. Thus, for example, can be selected directly between a passive regeneration strategy 22, a first, active regeneration strategy 23, a second active regeneration strategy 24 and a third regeneration strategy 25. The active regeneration strategies differ in each case by different interventions on the operation of the internal combustion engine, especially by means of engine control unit. These regeneration strategies are alternatively provided by the method. Following the execution of one of these regeneration strategies, it can then be queried whether the measure achieved was sufficient. In this checking step 26, it can then be decided to repeat the regeneration, because, for example, the particle filter could not yet be burned sufficiently. On the other hand, however, it is also possible, for example due to the driving behavior of the user of the road vehicle, to adjust to the situation that one of the regeneration strategies used should now be replaced by another regeneration strategy.

These possibilities, which are presented schematically in each case, only show examples of different process sequences. In particular, the process sequences may comprise mixtures of the different designs resulting from FIGS. 2 and 3, as well as additional elements which have so far received no mention as queries. In particular, the regeneration strategy is embedded in a driving strategy which, for example, can be performed by the engine control unit depending on the user. This includes, in particular, the possibility that self-learning systems are used in this case.

Claims

claims

A method implemented in an engine control system of a vehicle, the method performing a particulate filter regeneration in an Otto-principle internal combustion engine of the vehicle, wherein the particulate filter regeneration pursues a multi-stage regeneration strategy, in which after a first stage passive regeneration strategy is executable, at least the following steps are executable:

- check whether the soot content exceeds a specified maximum value,

Check that the success of the first active regeneration strategy is sufficient

2. The method according to claim 1, characterized in that after the execution of the second active regeneration strategy, the success of the second active regeneration strategy is checked again, which may be followed by at least one further third regeneration strategy if unsatisfactory.

3. The method of claim 1 or 2, characterized in that in the first active regeneration strategy is intervened in the operating strategy of the vehicle such that the probability is increased, in a fuel cut-off phase with hot exhaust gas temperatures to get.

4. The method according to claim 3, characterized in that in the first active regeneration strategy, the switch-on of the fuel cut-off are adjusted, preferably a lower speed threshold is selected.

5. The method according to claim 3 or 4, characterized in that in the first active regeneration strategy certain transmission strategies are not allowed.

6. The method according to claim 1, wherein the second active regeneration strategy has a higher regeneration efficiency than the first active regeneration strategy, wherein the second active regeneration strategy has a greater influence on the drivability of the vehicle than the first active regeneration strategy ,

7. The method according to claim 6, characterized in that the third active regeneration strategy has a higher regeneration efficiency than the second active regeneration strategy, wherein the third active regeneration strategy has a greater influence on the drivability of the vehicle than the second active regeneration strategy.

8. The method according to any one of claims 1 to 7, characterized in that in the second active regeneration strategy, the internal combustion engine is operated at a low partial load in a lean operation with setting a spark retard to increase an exhaust gas temperature.

9. Method according to one of claims 1 to 8, characterized in that, in the third active regeneration strategy, switching off a fuel injection in at least one cylinder of the combustion engine is provided in a low partial load point.

10. The method according to any one of the preceding claims, characterized in that when determining the soot content of the particulate filter, an estimate by means of a Rußentstehungsmodells takes place, which at least one of the following factors, preferably the following factors considered: an oil consumption, a Rußausstoß depending on a speed and / or a load, one or more correction factors, which are determined as a function of an implemented wall ^¬ filmmodell an Otto engine combustion, and one or more environmental conditions.

11. The method according to any one of the preceding claims, characterized in that when determining the Rußgehalts a combustion model is used, which makes a quantitative estimate of a particulate filter regeneration based on an existing oxygen content, an exhaust gas mass flow and a particulate filter temperature.

12. The method according to any one of the preceding claims, characterized in that a particle-related value, preferably a particle number and / or a particle mass is determined with respect to the particulate filter, wherein a regeneration of the particulate filter is preferably triggered when a predetermined maximum value is exceeded.

13. Vehicle with an operating according to the Otto principle internal combustion engine with a direct injection and / or intake manifold injection with an exhaust system in which a particulate filter is arranged, with an engine control unit, wherein the engine control unit has a volatile and a non-volatile memory, with an implemented method to the particle filter generation, preferably according to one of the preceding claims 1 to 12, wherein at least one passive particle filter regeneration strategy is executable and at least two different active particle filter regeneration strategies in the are implemented and with an implemented determination of a loading state of the particulate filter, which is preferably implemented in the engine control unit.

Vehicle according to claim 13, characterized in that at least each active regeneration strategy has a different impact on a performance of the internal combustion engine.

Vehicle according to claim 13 or 14, characterized in that at least one of the active regeneration strategies is linked to a limitation of a transient operating behavior of the internal combustion engine.

Vehicle according to claim 13, 14 or 15, characterized in that the vehicle has an automatic transmission, wherein the automatic transmission has different modes of operation adjustable, wherein each mode of operation is assigned a mutually different regeneration strategy.