WO2014199044A1

WO2014199044A1 - Method for limiting the ageing of a catalyst in a motor vehicle exhaust line

Info

Publication number: WO2014199044A1
Application number: PCT/FR2014/051291
Authority: WO
Inventors: Sébastien FAURE; Pascal Folliot
Original assignee: Peugeot Citroen Automobiles Sa
Priority date: 2013-06-11
Filing date: 2014-06-02
Publication date: 2014-12-18
Also published as: CN105324557B; EP3008301A1; FR3006709A1; FR3006709B1; CN105324557A

Abstract

The invention concerns a method for limiting the ageing of at least one catalyst in an exhaust line of a motor vehicle, said catalyst being located upstream of a particle filter, the temperature upstream of the filter being, during a regeneration, sufficient to burn the soot that it contains, said temperature being obtained by additional injections of fuel into the line during regeneration, characterised by the step of determining a temperature setpoint (PF Tupstream Setpoint) upstream from the filter and a dosing setpoint (Diesel Dosing Setpoint) for the additional injections of fuel, the two setpoints being determined on the basis of the distance travelled by the vehicle since a new catalyst was provided (Distance since new DOC) or a model of catalyst damage (DOC Damage Model) according to at least the estimated or measured temperature (estimated or measured Tintra DOC) of the catalyst.

Description

METHOD FOR LIMITING THE AGING OF A CATALYST IN AN EXHAUST LINE OF A MOTOR VEHICLE

The present invention relates to a method of limiting the aging of at least one catalyst in an exhaust line of a motor vehicle, or these catalysts can be a catalyst for oxidation of carbon monoxide or CO and hydrocarbons or HC and a nitrogen oxide reduction catalyst. This limiting method is carried out by adaptation of the particle filter regenerations, advantageously the particulate filter being impregnated or not.

In what follows, it will be taken as an example of a motor vehicle exhaust line DIESEL type. This example is not limiting and the motor vehicle can also be a gasoline vehicle, the catalyst is advantageously an oxidation catalyst, including a three-way catalyst.

Such an exhaust line for the depollution treatment of gases flowing through it is equipped in general with:

a diesel oxidation catalyst, hereinafter referred to as DOC catalyst treating carbon monoxide or CO and hydrocarbons or HC,

an optional post-treatment means for the oxides of nitrogen or NOx downstream of the DOC catalyst, for example a selective catalytic reduction system, hereinafter referred to as the SCR system,

an impregnable or non-impregnable particulate filter being disposed downstream of the DOC catalyst, the DOC catalyst being the place of the exotherm for the regeneration of the particulate filter.

The succession of regenerations of the particulate filter is responsible for the accelerated aging of the catalytic loaves ensuring the oxidation-reduction functions of CO, HC and NOx in the respective catalysts present in the exhaust line. The heat reached in the line is in fact of the order of 450 ° C to 550 ° C upstream of the particulate filter and even more upstream of the DOC catalyst and the SCR system.

Frequently, it is the DOC catalyst for a diesel or oxidation catalyst for a gasoline vehicle that causes an exotherm, this by combustion of hydrocarbons during the post-injection of fuel for upstream of and in the particle filter there remains a sufficient temperature to burn the soot, even with the losses in the line due for example to the wall and the other bricks of pollution, etc. The impregnations of the catalyst causing the exotherm then age because of temperature gradients and absolute temperature values prevailing at the catalyst. Oxidation catalyst aging models are known based on the impact of a succession of exotherms or on a prolonged stay at high oven temperature as a function of catalyst initiation curves. These models are embedded or taken in the margin of design to define the good level of concentration in precious metals to ensure the right level of oxidation of HC and CO.

[0007] There is also a so-called FCLO or rapid catalyst initiation strategy making it possible to make up at least a catalyst aging with a shift of the priming curve towards higher temperatures, this by degrading the combustion of the engine at the same time. source to heat the DOC catalyst faster. Indeed, the initiation of a catalyst is effective only if the temperature of the exhaust gas has reached a certain level, for example between 250 ° C and 270 ° C. It therefore takes a minimum time for the catalyst to function effectively.

However, these two strategies are passive and do not exploit the possibilities of slowing the aging of the catalyst offered by the regeneration of the particulate filter, this in particular but not only in the case of an additive particle filter. Under certain rolling conditions, the aging of the catalyst can be reduced without affecting the efficiency of the regeneration of the particulate filter by combustion of the soot it contains.

For this purpose, it has been developed an upstream temperature setpoint strategy of the particulate filter in dependence of the soot mass estimated in the particulate filter. In the case of an additive particulate filter, a fixed additive set point is provided. The more additive is added, the lower the significant combustion temperature of the soot but the more the particle filter is clogged.

It is also possible to make this dosing set depend on the rolling profile. Depending on the soot loading, a rolling descriptor is used to decide when to start regeneration. The more the particulate filter is sooty and the more it is allowed to start regenerations at low speed for example.

[001 1] EP-A-1 669 580 discloses a method for controlling the regeneration of an internal combustion engine particle filter comprising determining the efficiency of a catalyst disposed in the exhaust in upstream of the filter. This method provides adjustment of at least one operating parameter of the engine to increase the temperature of the exhaust gas upstream of the catalyst to compensate for the reduction in catalyst efficiency due to aging. If this document takes into account the aging of the catalyst disposed upstream of the particulate filter, it does not propose any solution to reduce this aging.

The solution proposed in this document serves only to overcome the progressive aging of the catalyst and therefore to compensate for its lower ability to exotherm to obtain the temperature upstream of the particulate filter sufficient to perform a regeneration of the filter.

Therefore, the problem underlying the invention is to slow the aging of a catalyst disposed upstream of a particulate filter in a motor vehicle exhaust line, this aging being caused by temperatures. too high in the catalyst during regeneration of the particulate filter.

To achieve this objective, there is provided according to the invention a method of limiting the aging of at least one catalyst in an exhaust line of a motor vehicle, this catalyst being upstream of a filter to particles in the line, the temperature upstream of the particulate filter being, during a regeneration, sufficient to burn the soot it contains, this temperature being obtained by additional injections of fuel in the line made during the regeneration, characterized by the step of determining a temperature setpoint upstream of the particulate filter and an additional fuel injection dosing setpoint, the determinations of the two setpoints being made as a function of the distance traveled by the vehicle since placing a new catalyst or a model of damage of the catalyst according to at least the estimated or measured temperature of the catalyst.

The technical effect is to obtain a reduction of at least one of the temperature values between the temperature reached in the catalyst and the exotherm existing between the downstream and upstream temperatures of the catalyst, by triggering regenerations with temperatures. upstream of the catalyst higher and higher and downstream temperatures increasingly low.

Advantageously, the upstream temperature setpoint is corrected taking into account the soot mass estimated inside the particulate filter and, when a running severity threshold exists for the authorization of the launch of a regeneration of the filter, this threshold of severity is replaced by a threshold of severity corrected taking into account the mass of soot and the distance traveled by the vehicle since the introduction of a new catalyst or model of damage to the catalyst. Advantageously, the rolling severity is calculated by a running severity descriptor taking into account at least the parameters of speed, acceleration and engine speed of the vehicle and the thermal parameters of the exhaust line.

Advantageously, the method comprises the step of determining maximum and minimum upstream temperatures of the particulate filter as well as maximum and minimum fuel injection dosages, these determinations of maximum and minimum temperature and maximum and minimum dosage are according to the distance traveled by the vehicle since the introduction of a new particulate filter or particulate filter fouling model according to at least several operating parameters of the vehicle whose amount of oil lubrication and the amount of additive, the temperature and dosing setpoints being respectively between the maximum and minimum temperatures and the maximum and minimum dosages.

Advantageously, the distance traveled by the vehicle since the introduction of a new particulate filter and the fouling model of the particulate filter are taken together for the maximum and minimum determinations of temperature and dosage and, if necessary, for the correction of the severity threshold, the distance being corrected according to a fouling target of the particulate filter, the value according to the fouling model being subtracted from the value according to the fouling target and regulated beforehand. be taken for maximum and minimum determinations of temperature and dosage.

Advantageously, the distance traveled by the vehicle since the introduction of a new catalyst and the model of damage to the catalyst are taken together for the determination of the temperature and dosing instructions and, where appropriate, for the correction of the severity threshold, the distance being corrected according to a target of damage of the catalyst, the value according to the damage model being subtracted from the value according to the target of damage and regulated before being taken for the determination of the temperature and dosing instructions and, if necessary, for the correction of the severity threshold.

Advantageously, the regulation is a proportional integral control or Pl. The invention also relates to a motor vehicle having at least one catalyst and a particulate filter in its exhaust line, the catalyst being upstream of the particulate filter, characterized in that the catalyst is protected from aging by such a method of limiting aging.

[0023] Advantageously, the catalyst is a gasoline or diesel oxidation catalyst.

Advantageously, the exhaust line also comprises at least one SCR system or a NOx trap, the SCR system or the NOx trap being disposed between the oxidation catalyst and the particulate filter or being impregnated in the filter. with particles.

Other features, objects and advantages of the present invention will appear on reading the detailed description which follows and with reference to the accompanying drawings given by way of non-limiting examples and in which:

FIGS. 1 to 5 are respective schematic representations of a first, second, third, fourth and fifth embodiment of a method for limiting the aging of at least one catalyst in an exhaust line of a vehicle automobile according to the present invention.

In general, a particulate filter is filled during the driving of the motor vehicle particles, mainly soot particles and must be regularly regenerated to remove by combustion particles it contains.

A regeneration consists of carrying the particle filter at a very high temperature. For this, it is carried out additional injections of fuel, also called post-injections, in the exhaust line of the vehicle, these additional injections being completely invisible to the driver. These additional injections lead to a sharp increase in the temperature of the exhaust gases, resulting in a rise in temperature upstream of and in the filter. With this rise in temperature, soot, essentially composed of carbon, transform into carbon dioxide and water vapor then eliminated through the exhaust line.

It follows that a regeneration can be triggered only if the temperature upstream of or in the filter is sufficiently high. For an exhaust line comprising an oxidation catalyst positioned upstream of the particulate filter, it is during the catalysis reactions taking place in this catalyst that a release of heat or exotherm occurs. It has been seen previously that it is the amplitude of the exotherm of the catalyst, the difference between its downstream temperature and its upstream temperature, which is the source of its aging. For simplicity, it will be assumed that this upstream catalyst is an oxidation catalyst and that the downstream temperature of the The catalyst is also considered to be the temperature upstream of the particulate filter, although an SCR system or a NOx trap may be interposed between the catalyst and the filter.

The advantage of the present invention is both to trigger regenerations with DOC catalyst upstream temperatures higher and higher and temperatures downstream of the catalyst, or indirectly upstream temperatures of the particulate filter, more and more weak, this to decrease the difference between the exit and the entry of the catalyst. This can be done by increasing the dosage of additional fuel injections to lower the temperature at which soot begins to burn significantly.

Thus, the maximum temperature reached in the catalyst and the temperature exotherm resulting from the difference in the downstream temperature and the upstream temperature of the catalyst can be reduced. It is these two quantities that are directly correlated to the degradation phenomena of the catalyst efficiency.

This is especially true for an oxidation catalyst, because it is he who is the place of the exotherm for the regeneration of the particulate filter. A NOX reduction catalyst upstream of the particulate filter, of the SCR system type, mainly ages by its maximum temperature, its exotherm being limited because the SCR system does not produce an exotherm. In this case, it is mainly the maximum temperature reached in the catalyst that should be reduced, which can be done according to an alternative embodiment of the present invention.

Referring to Figures 1 to 5, according to the present invention, the method of limiting the aging of at least one catalyst in an exhaust line of a motor vehicle, the catalyst being upstream of a particulate filter in the line, comprises the step of determining an upstream temperature setpoint "Tamont FAP setpoint" of the particulate filter and an additional fuel injection metering setpoint "Fuel Dosing Setpoint", this fuel is not however limited to diesel, the determination of the two instructions being made according to the distance traveled by the vehicle since the installation of a new catalyst "Distance from Doc nine" or a model of Damage "Model Damage Doc" of the catalyst according to at least the estimated or measured temperature "Tintra Doc estimated or measured" catalyst.

Advantageously, the upstream temperature setpoint is corrected by taking into account the soot mass estimated "Estimated intra-FAP soot mass" inside the particulate filter and, when a rolling severity threshold "threshold_sévérité_roulage_pour_RGFAP" exist for authorization to launch a regeneration of the filter, this severity threshold is corrected as "rolling severity threshold for RGFAP" taking into account the mass of soot "Estimated intra-FAP soot mass" and the distance traveled by the vehicle since the installation a new "Distance from Doc New" catalyst or the fouling model of the "FAP fouling model" particulate filter.

In the embodiment shown in Figure 1, it is used only the information on the distance traveled by the vehicle since the establishment of a new catalyst "Distance from Doc nine". This information is already present in the vehicle calculator. It is then estimated that the aging of the catalyst is relatively proportional to its operating distance. The older the catalyst, the longer it has traveled, the lower the upstream temperature set point "Tamont FAP setpoint" of the particulate filter, while increasing the dosing setpoint "Gas dosing setpoint".

The older the catalyst, the more it is appropriate to start regenerations only when the vehicle rolls less severely. This is limited to a certain extent because there should be no more opportunities for regeneration of the particulate filter. This correction is made as a function of the distance traveled from a new "Distance from Doc New" catalyst, but also from the estimated soot mass "estimated intra-FAP soot mass" in the particulate filter in order to inhibit this feature when the Particle filter begins to become too charged.

Increasing the dosing setpoint "Gas dosing setpoint" to limit the aging of the catalyst has the effect of prematurely fouling the particulate filter, which protects the catalyst to the detriment of the particulate filter. The temperature and dosing setpoint determinations should therefore be limited accordingly.

Advantageously, the method comprises the maximum upstream temperature determination step "TamontFAP max" and minimum "TamontFAP min" of the particulate filter as well as maximum dosages "Dosage_max" and minimum "Dosage_min" of fuel injection, these maximum and minimum determinations of temperature and dosing are based on the distance traveled by the vehicle since the introduction of a new particle filter "Distance from FAP nine" or a fouling model "Model Fouling FAP "of the particulate filter according to at least several operating parameters of the vehicle including the amount of" Qte oil "lubricating oil and the amount of additive" Qte Additive ", the temperature instructions" Set Tamont FAP "and dosing "Diesel Dosage Set" being included between the maximum temperatures "TamontFAP max" and minimum "TamontFAP min" and the maximum dosages "Dosage_max" and minimum "Dosage_min".

The maximum temperatures "TamontFAP max" and minimum "TamontFAP min" and the maximum dosages "Dosage_max" and minimum "Dosage_min" can be determined each from maps that can be contained in the calculator and prepared beforehand by trial and / or or calculated according to the distance traveled by the vehicle since the introduction of a new particle filter "Distance from FAP nine" or a fouling model "FAP fouling model" of the particulate filter according to at least several vehicle operating parameters including the amount of "Qte oil" lubricating oil and the amount of "Qte Additive" additive.

Maximum and minimum determinations of temperature and dosage based on the distance traveled by the vehicle since the introduction of a new particle filter "Distance since FAP nine" are shown in Figure 1 while maximum and minimum determinations of temperature and dosage based on a fouling model "FAP fouling model" of the particulate filter are shown in Figure 2, Figures 3 to 5 showing in association a fouling model "FAP fouling model" and a distance traveled by the vehicle "Distance from FAP nine" for these determinations.

A particle filter as a catalyst is made to last at least 160,000 km according to the regulations. However, for an oxidation catalyst, the in-service compliance control or ISC provides for CO / HC / NOx decontamination a service life of up to 5 years or 100,000km. The particle filter, on the other hand, has a lifespan of around 200,000 km.

Thus, it can be envisaged two work areas: a first zone where the particulate filter and the oxidation catalyst must be completely effective and a second zone where it is more particulate filter that should not too much have impacts, because there is a risk of loss of power from the engine due to clogging of the particulate filter and lighting of the lights at the driving position due to the overload of the particulate filter.

It may therefore be an increase in the dosing setpoint "Dosage Dosage Gasoil" early life of the particulate filter and catalyst and a decrease of this set beyond 100,000 km to not impact too much. clogging of the particulate filter. It can be done inversely for the upstream temperature setpoint "Setpoint Tamont FAP" of the filter. It is possible to reduce the triggering conditions of regeneration of the particulate filter at the beginning of the life of the catalyst and particulate filter and désévériser beyond 100,000km to avoid overloading the particulate filter.

As previously mentioned, it is possible to use a damage model "Model Damage Doc" for the determination of the temperature setpoints "Setpoint Tamont FAP" and dosing "Setpoint Dosage Gasoil", this as an alternative or in combination with the distance traveled from a new catalyst "Distance from Doc nine".

[0044] Figure 1 shows determination of instructions "Set Tamont FAP" and "Dosage Dosing Gasoil" only depending on the distance traveled from a new catalyst "distance from Doc nine". Figure 2 shows "Setpoint Tamont FAP" and "Diesel Dosage Setpoint" setpoint determinations based solely on the damage model "Damage Model Doc" while Figures 3-5 show the distance traveled "Distance from Doc New" taken in common with the damage model "Model Damage Doc" for the determination of the instructions "Setpoint Tamont FAP" and "Setpoint Dosage Gasoil" and also, if necessary, for the correction of the threshold of severity "Threshold severity in running for RGFAP ".

The instruction "TAM Tamont Setpoint" can be determined from a map that establishes according to the distance traveled from a new catalyst "distance from Doc nine" and / or depending on the model of damage "Model Damage Doc "according to the variants, and soot mass" Soil mass intra FAP estimated ", the setpoint" Setpoint Tamont FAP "that the strategy will impose particulate filter. The map can be contained in the calculator. The mapping is determined beforehand by trial and by calculation. The setpoint "Set point Tamont FAP" is limited by the maximum temperature values "TamontFAP max" and minimum "TamontFAP min".

The instruction "Dosage Dosage Gasoil" can be determined from a map that establishes depending on the distance traveled from a new catalyst "distance from Doc nine" and / or depending on the model of damage "Model Damage Doc "according to the variants, the instruction" Dosage Dosage Gasoil "that the strategy will impose. The map can be contained in the calculator. The mapping is determined beforehand by trial and by calculation. The "Diesel dosing setpoint" instruction is limited by the maximum dosing values "Dosage_max" and minimum "Dosage_min". In Figures 3 to 5, the damage model "Dam Dam model" serves as a means of control to the determination by the distance traveled from a new catalyst "Distance from Doc nine". It can be fixed a target of damage of the catalyst "Target_damage_DOC" according to the mileage and be carried out the adaptation of the temperature instructions "Setpoint Tamont FAP" and dosing "Setpoint Dosage Gasoil" as well as, if necessary, the correction of the severity threshold "Rolling severity threshold for RGFAP" for regeneration of the particulate filter.

The distance traveled from a new catalyst "distance from Doc nine" is corrected according to a target of damage "Target_damage_DOC" of the catalyst, the value according to the model of damage "Model Damage Doc" being subtracted to the value according to the target of damage and regulated before being taken for the determination of the temperature setpoints "Setpoint Tamont FAP" and dosing "Setpoint Dosage Gasoil" and also, if necessary, for the correction of the threshold of severity "Threshold severity in rolling for RGFAP ".

Advantageously, the regulation is an integral proportional control or PI being performed with a PI controller, with advantageously a dead zone and an anti wind-up or anti-runaway of the integral. Other modes of regulation are also possible.

If the correction of the controller PI is negative, it is that it survives the catalyst with respect to the target "Target_damage_DOC" and that it is necessary to slow the aging by increasing the dosing setpoint "Gas dosing setpoint", in reducing the temperature setpoint "Tamont FAP setpoint" of the particulate filter and by tightening the conditions for triggering regenerations "rolling severity threshold for RGFAP".

Conversely, if the correction of the corrector PI is positive, it is that "under-aged" the catalyst relative to the target "Target_damage_DOC". It is therefore possible to favor the regeneration of the particulate filter by acting on the rolling severity threshold, thus reducing the dosing setpoint "Gas dosing setpoint" and thus of less aging the particulate filter and increasing the setpoint. "Tamont FAP Setpoint" temperature of the particulate filter.

As shown in FIG. 5, it is also possible to use such a regulation from the particle filter data for the maximum and minimum temperature determinations "Setpoint Tamont FAP" and the "Dosage Determination Gasoil" dosage. In this case, the distance traveled by the vehicle since the introduction of a new particle filter "Distance from FAP nine" and a fouling model "FAP fouling model" of the particulate filter can be taken into account. common for maximum and minimum determinations of temperature and dosing "Tamont FAP Setpoint" and "Gasoline Setpoint".

The distance traveled by the vehicle since the introduction of a new particle filter "Distance from FAP nine" is corrected according to a fouling target "FAP_fattening_catch" of the particulate filter, the value according to the model of fouling "FAP fouling model" being subtracted to the value according to the fouling target "FAP_crubbing_target" and regulated before being taken for the maximum and minimum temperature and dosing determinations "Setpoint Tamont FAP" and "Setpoint dosage Gasoil".

If the particulate filter fouls slower than expected, we can allow a longer protection of the catalyst, in other words an increase in dosage "Gasoil Dosage Setpoint" and a decrease in the setpoint "Setpoint Tamont FAP". If the particulate filter clogs faster than expected, the catalyst protection is canceled or reduced so as not to compromise the proper functioning of the particulate filter and its aging.

The great advantage of the present invention, both for a diesel engine and gasoline, is to delay or control the aging of the catalyst and, if necessary other catalytic bricks located in the exhaust line of the motor vehicle.

The decontamination lines adapted to this invention are as follows, being taken from upstream to downstream for the order of appearance of the depollution means in the exhaust line:

an oxidation catalyst and a particulate filter,

an oxidation catalyst, a particulate filter and an SCR system,

an oxidation catalyst, a particulate filter and a NOx trap,

an oxidation catalyst, an SCR system and a particulate filter,

an oxidation catalyst and a particulate filter with SCR impregnation,

an oxidation catalyst, a NOx trap and a particulate filter,

an oxidation catalyst and a particulate filter with NOx trap impregnation. The method according to the invention can be used to optimize the sizing of the oxidation catalyst, in particular the weight of precious metals for CO and HC decontamination and the dimensioning of the intermediate decontamination bricks that can undergo the effects. the exotherm of the catalyst using the room for maneuver that can offer an additive particulate filter in terms of controlling the regeneration of the particulate filter and a severity of the conditions for triggering regenerations. This allows a gain in land cost or PRF.

The invention is not limited to the described and illustrated embodiments which have been given only as examples.

Claims

A method for limiting the aging of at least one catalyst in an exhaust line of a motor vehicle, said catalyst being upstream of a particulate filter in the line, the temperature upstream of the particulate filter being, when a regeneration, sufficient to burn the soot it contains, this temperature being obtained by additional injections of fuel in the line made during regeneration, characterized by the step of determining a temperature setpoint (Instructions Tamont FAP) upstream of the particulate filter and a dosing setpoint (Fuel Dosing Setpoint) of additional fuel injection, the determinations of the two setpoints (Setpoint Tamont FAP, Setpoint dosing Gasoil) being made according to the distance traveled by the vehicle since the installation of a new catalyst (Distance from Doc nine) or a model of damage (Model Damage Doc) of the catalyst according to at least the estimated or measured temperature (Tintra Doc estimated or measured) of the catalyst.

A method according to claim 1, wherein the upstream temperature setpoint (Tamont Setpoint FAP) is corrected taking into account the estimated soot mass (estimated intra-FAP soot mass) within the particulate filter and, when a threshold of severity during taxiing (RGFAP_seuter_slope_speed) exists for the authorization to launch a regeneration of the filter, this severity threshold is replaced by a corrected severity threshold (Rolling severity threshold for RGFAP) taking into account the mass of soot ( Estimated intra-FAP soot mass) and the distance traveled by the vehicle since the installation of a new catalyst (Distance from Doc Nine) or the model of damage (Model Damage Doc) of the catalyst.

Method according to Claim 2, in which the rolling severity is calculated by a running severity descriptor taking into account at least the vehicle speed, acceleration and engine speed parameters and the exhaust line thermal parameters. .

A method according to any one of the preceding claims, which comprises the step of determining maximum and minimum upstream temperatures (TamontFAP max, TamontFAP min) of the particle filter as well as maximum and minimum dosages (Dosage_max, Dosage_min) of injection of fuel, these maximum and minimum temperature determinations (TamontFAP max, TamontFAP min) and maximum and minimum dosage (Dosage_max, Dosage_min) are based on the distance traveled by the vehicle since installation a new particulate filter (Distance from FAP new) or a fouling model (Model FAP FAP) of the particulate filter according to at least several operating parameters of the vehicle whose quantity of oil (Qt oil) of lubrication and the amount of additive (Qt Additive), the temperature and dosing instructions (Tamont FAP Setpoint and Diesel Dosage Setpoint) being between the maximum and minimum temperatures respectively (TamontFAP max, TamontFAP min) and the maximum and minimum dosages (Dosage_max, Dosage_min).

A method according to claim 4, wherein the distance traveled by the vehicle since the introduction of a new particulate filter (Distance from FAP nine) and the fouling model (FAP fouling model) of the particulate filter are taken into account. for the maximum and minimum temperature determinations (TamontFAP max, TamontFAP min) and dosing (Dosage_max, Dosage_min) and, if applicable, for the correction of the severity threshold (Rolling severity threshold for RGFAP), the distance (Distance since FAP nine) being corrected according to a fouling target (Particulate_FAPtarget_FAP) of the particulate filter, the value according to the fouling model (FAP fouling model) being subtracted from the value according to the fouling target (FAP_crubbing_target) and regulated beforehand to be taken for maximum and minimum temperature determinations (TamontFAP max, TamontFAP min) and dosing (Dosage_max, Dosage_min).

A method as claimed in any one of the preceding claims, wherein the distance traveled by the vehicle since the introduction of a new catalyst (Distance from Doc New) and the Damage Model (Model Damage Doc) of the catalyst are taken into account. for the determination of the temperature and dosing setpoints (Setpoint Tamont FAP, Setpoint Gasoil), the distance (Distance from Doc nine) being corrected according to a target of damage (Target_damage_DOC) of the catalyst, the value according to the model of Damage (Model Damage Doc) is subtracted to the value according to the target of damage (Target_damage_DOC) and regulated before being taken for the determination of the temperature and dosing setpoints (Setpoint Tamont FAP, Setpoint Dosage Gasoil).

Method according to claim 5 or 6, wherein the regulation is an integral proportional control or P1.

Motor vehicle having at least one catalyst and a particulate filter in its exhaust line, the catalyst being upstream of the particulate filter, characterized in that the catalyst is protected from aging by a method of aging limitation according to any one of the preceding claims.

9. Motor vehicle according to claim 8, wherein the catalyst is a gasoline or diesel oxidation catalyst.

The motor vehicle according to claim 9, wherein the exhaust line also comprises at least one selective catalytic reduction system or a NOx trap, the SCR system or the NOx trap being disposed between the oxidation catalyst and the particulate filter or being impregnated in the particulate filter.