Method for the conditional regeneration of a particulate filter and implementation device

Abstract

The present invention relates to a method for regenerating a particulate filter (16) of an internal combustion engine vehicle (10) and an implementing device. The method comprises the following steps: a) recording: - two first threshold values ​​M1 and M2; - at least two second threshold values ​​Vs1 and Vs2; - at least two third threshold values ​​Vi1 and Vi2; b) evaluating a quantity M of particles contained in said filter (16), an instantaneous velocity Vs and another velocity parameter Vi; and, c) triggering the regeneration of said filter (16): - if a last regeneration has taken place for more than a first predetermined period Δ1 and, if M > M1, Vs > Vs1 and Vi > Vi1; or, - if said last regeneration has taken place for more than a second predetermined period Δ2, Δ2 being greater than Δ1, and, if M > M2, Vs > Vs2 and Vi > Vi2.In step a), the instantaneous position and the predicted future course are recorded, and in step b), at least one other velocity parameter Vi is evaluated as a function of said instantaneous position and said predicted future course. Figure to be published with the abbreviation: Fig. 1.

Description

Title of the invention: Method for conditional regeneration of a particulate filter and device for implementing it

[0001] The present invention relates to a method for conditional regeneration of a particulate filter of a motor vehicle with a thermal engine and to a device for implementing it.

[0002] One area of ​​application envisaged is in particular that of diesel vehicles, which emit combustion gases loaded with fine particles and soot particles.

[0003] Also, it is necessary to retain these particles so as not to release them into the atmosphere. And to do this, a particle filter is implemented on the combustion gas exhaust pipe.

[0004] In a known manner, the particles accumulated in this filter are degraded during the normal operation of the engine in lean mixture, that is to say they are burned during phases triggered sequentially. During these phases, the operating mode of the engine is modified, depending on the operating conditions of the motor vehicle in driving situation. Indeed, the accumulation of particles inside the filter tends to reduce its filtration efficiency and, moreover, causes a deterioration in the performance of the engine because it creates a back pressure downstream of the engine. In the extreme, the particles clog the filter and it is necessary to replace it.

[0005] In order to degrade the particles accumulated in the filter at the appropriate time, that is to say to cause their combustion, a plurality of parameters are measured and evaluated and compared respectively to a plurality of threshold values ​​in order to be able to trigger the regeneration of the particle filter. This regeneration, or purging of the particle filter, is carried out by combustion of the particles themselves, inside the filter and thanks to a supply of fuel. The higher the speed of the motor vehicle and the longer it has been so for, the more efficiently and effectively the regeneration of the particle filter will be carried out, because the temperature of the filter will be higher and the necessary fuel consumption will be low.

[0006] One of the first variables to be taken into account is therefore, above all, the quantity of particles accumulated inside the filter. Thus, the mass of particles is evaluated in a known manner by measuring the flow rate of the gases passing through the filter and the pressure difference between the inlet of the filter and its outlet. The mass of particles is a function, mapped by prior tests, of the flow rate and said pressure difference.

[0007] Then, the variables related to the vehicle speed are taken into account to trigger the regeneration of the filter. This includes the instantaneous speed which is given by the usual equipment of the motor vehicle and also the average speed which precedes it. For example, the average speed over the two or three minutes preceding the measurement of the instantaneous speed is evaluated.

[0008] Also, care is taken to space out the regeneration phases of the particle filter, and to do this, account is taken of the time interval between two consecutive purges of the particle filter.

[0009] Furthermore, if the favorable conditions for triggering the regeneration of the particle filter are those of a high speed of the motor vehicle over a long period of time, for example on the motorway, these conditions are not always met, because their presence depends on the use of the vehicle by its driver, and yet, it is necessary to purge the particle filter when the quantity of particles it contains is too large.

[0010] Therefore, according to known methods of implementation, the regeneration of the particle filter is triggered under more or less favorable vehicle driving conditions.

[0011] Thus, it is known to provide, for example, four calibrated states between favorable regeneration conditions where the vehicle travels at high speed and forced conditions where the vehicle travels at low speed, depending on the quantity of particles accumulated in the filter, the instantaneous speed, the past average speed and the time which has elapsed since the last triggering of the regeneration.

[0012] And on each of the calibrated states, threshold values ​​are provided for each of the variables. In the calibrated state corresponding to the favorable regeneration conditions, the threshold of the quantity of particles accumulated in the filter and the threshold of time between two consecutive purges are the lowest compared to the thresholds corresponding to the less favorable regeneration conditions, while the thresholds of the average speed and the instantaneous speed are the highest.

[0013] When for a given calibrated state, at least one of the variables does not reach the threshold value, then the value of the variables is checked respectively in relation to their threshold value in the following less favorable calibrated state. And this is done until the purge is triggered.

[0014] It will be observed that the least favorable calibrated state corresponds to conditions where the values ​​of the thresholds of the operating parameters of the vehicle are very little restrictive so as to be able to ensure the purging of the particle filter whatever the cost for the efficiency and effectiveness of the process.

[0015] Despite all these precautions, the regeneration of the particle filter can be hampered if, for example, immediately after the purge is triggered, the instantaneous speed of the vehicle drops suddenly. This is the case, for example, when a vehicle is at high speed on a fast lane and that regeneration is triggered just before leaving the lane. Because in fact, the regeneration conditions which were very favorable, then become much less favorable for the efficiency of the regeneration and the additional fuel consumption to be implemented for the particle combustion reaction.

[0016] Therefore, a problem which arises and which the present invention aims to solve is to take into account parameters making it possible to trigger regeneration under the most favorable conditions and to avoid the regeneration process being interrupted.

[0017] For this purpose, and according to a first object, a method is proposed for the conditional regeneration of a particle filter of a motor vehicle with a thermal engine while driving, comprising the following steps: a) we record: - at least two first threshold values ​​Ml and M2, corresponding respectively to quantities of particles contained in said particle filter, Ml being less than M2; - at least two second threshold values ​​Vsl and Vs2, corresponding respectively to instantaneous speeds of said motor vehicle, Vsl being greater than Vs2; - at least two third threshold values ​​Vil and Vi2, corresponding respectively to another speed parameter of said motor vehicle, Vil being greater than Vi2; b) a quantity M of particles contained in said particle filter, an instantaneous speed Vs and another speed parameter Vi of said vehicle are evaluated; and, c) the regeneration of said particulate filter is caused: - if a last regeneration has taken place more than a first predetermined period of time Al and, if M > Ml, Vs > Vsl and Vi > Vil; or, - if said last regeneration has taken place for more than a second predetermined period of time A2, A2 being greater than Al, and, if M > M2, Vs > Vs2 and Vi > Vi2. In step a), the instantaneous position and the foreseeable future travel of said motor vehicle are recorded, and in step b), said at least one other speed parameter Vi is evaluated as a function of said instantaneous position and said foreseeable future travel.

[0018] Thus, a characteristic of the invention lies in taking into account the instantaneous position of the vehicle and the future course of the vehicle to evaluate the probable evolution of the speed parameters, and thus, to be able to trigger the regeneration of the particle filter. Consequently, the future speed parameters are taken into account to trigger the regeneration of the filter and no longer the past speed parameters.

[0019] In this way, the regeneration of the particle filter can be triggered by significantly increasing the probability that the regeneration process will not be interrupted, or more precisely, that it will operate to completion under the most favorable conditions.

[0020] It will be observed that only two calibrated states are defined for all the variables considered: Ml, Vsl, Vil, Al and M2, Vs2, Vi2, A2. However, as will be explained in more detail in the remainder of the description, it is possible to define a plurality of calibrated states, for example five calibrated states, so as to be able to purge the particle filter under the most favorable conditions possible. The number of states defined must be compatible with the calculation capabilities of the on-board computer and the associated reaction time.

[0021] According to a particularly advantageous embodiment of the invention, said instantaneous position of said motor vehicle is recorded by capturing signals from a satellite positioning system. This instantaneous position can then be compared in real time with cartographic information making it possible to precisely determine the future course of the motor vehicle. This cartographic information can be stored in a memory of the on-board computer of the motor vehicle.

[0022] Advantageously, said instantaneous position and said foreseeable future course are recorded by capturing the signals from an advanced driver assistance system. For example, signals provided under the known “ADASIS” or “Google VMS” protocol are captured, using the positioning data and the cartographic information at each instant to provide information on the future horizon of the vehicle during the next kilometers, for example the next eight kilometers.

[0023] According to a particularly advantageous embodiment of the invention, said other speed parameter Vi corresponds to the average speed Vmoy evaluated as a function of said foreseeable future travel and said instantaneous position. Indeed, since the instantaneous speed is known, it is easy to evaluate the average speed Vmoy, for example over the next eight kilometers that the vehicle will travel. Consequently, from this evaluated average speed Vmoy, if the other parameters satisfy the threshold values, the regeneration of the particles in the filter can be carried out without it being interrupted.

[0024] According to a preferred embodiment, in step a) at least two fourth threshold values ​​Vj 1 and Vj2 are also recorded, corresponding respectively to minimum speeds, Vjl > Vj2, while in step b) a minimum speed Vmin is evaluated, and in step c) the regeneration of said particle filter is caused: - if a last regeneration took place more than said first predetermined time period Al and, if M > Ml, Vs > Vsl, Vi > Vil and if Vmin > Vjl; or, - if said last regeneration took place more than said second ... predetermined time A2, and, if M > M2, Vs > Vs2, Vi > Vi2 and if Vmin > Vj2.

[0025] Therefore, in addition to taking into account the average speed Vmoy foreseeable during the future journey of the motor vehicle, the minimum speed is also taken into account. In this way, it is ensured that the average speed Vmoy does not result from a significant excursion in the speed of the vehicle in the near future, whether downward or upward. A large variation in the speed of the vehicle would indeed compromise the efficiency of the regeneration.

[0026] Furthermore, and particularly advantageously, in step a) at least two fifth threshold values ​​T1 and T2 are recorded, corresponding respectively to particle filter inlet temperatures, T1 > T2, while in step b) the temperature T at the inlet of said particle filter is evaluated, and in that in step c) the regeneration of said particle filter is caused: - if a last regeneration has taken place more than the said first predetermined period of time Al and, if M > Ml, Vs > Vsl, Vi > Vil and if T > Tl; or, - if said last regeneration took place more than said second predetermined time period A2, and, if M > M2, Vs > Vs2, Vi > Vi2 and if T > T2.

[0027] Thus, by always defining only two calibrated states, a fifth variable T is taken into account corresponding to the inlet temperature of the particle filter so as to ensure, in addition, that the temperature of the filter is sufficiently high to allow perfect efficiency of the regeneration. Preferably, this temperature value is evaluated over the last 20 seconds preceding the evaluation of the instantaneous speed.

[0028] According to a particularly advantageous embodiment of the invention, in step b), the average slope P of said stroke is further evaluated as a function of said foreseeable future stroke and said instantaneous position, and in step c) the regeneration of said particle filter is caused if, in addition, said average slope is greater than or equal to zero.

[0029] Thus, another condition is added to trigger the regeneration of the particle filter in order to prevent the engine from being no longer under load. Indeed, when the vehicle is moving on a downward slope, the power required from the engine decreases considerably and consequently, reduces the efficiency of the regeneration.

[0030] Furthermore, in order to ensure that regeneration can be triggered under optimal conditions, the engine temperature is further evaluated by measuring the temperature of its coolant. Regeneration is then triggered if and only if this temperature is between a minimum temperature and a maximum temperature.

[0031] And in addition, we check that the pressure is higher than a minimum atmospheric pressure, so as to ensure that the conditions for combustion of the particles are optimal.

[0032] These last three conditions, relating to the operation of the heat engine, i.e. the power required from the engine, its temperature and the pressure, are respectively compared to the same thresholds in the two aforementioned calibrated states. This would also be the case if five calibrated states were defined.

[0033] According to yet another embodiment of the invention, it is also possible to define, on each of the two aforementioned calibrated states, several thresholds for the quantity of particles contained in the particle filter as a function of the mileage traveled. For example, a first threshold for the quantity of particles, through their mass, Mil, is defined for a mileage traveled less than 800 km, a second first threshold M21 lower than the first first threshold, for a mileage traveled between 800 km and 1000 km and a third first threshold M31 lower than the second first threshold for a mileage traveled greater than 1000 km. These values ​​are, of course, non-limiting, and the thresholds can be calibrated to different values.

[0034] In this way, the quantity M of particles evaluated is compared to the threshold corresponding to the number of kilometers traveled since the last regeneration.

[0035] This thus makes it possible to protect the system when the pressure or temperature sensors, for example, fail.

[0036] According to another object, a device is proposed for implementing the method of conditional regeneration of a particle filter of a motor vehicle with a thermal engine in a driving situation, as described above, said device comprising: a) a memory device for recording: - at least two first threshold values ​​M1 and M2, corresponding respectively to quantities of particles contained in said particle filter, M1 being less than M2; - at least two second threshold values ​​Vsl and Vs2, corresponding respectively to instantaneous speeds of said motor vehicle, Vsl being greater than Vs2; - at least two third threshold values ​​Vil and Vi2, corresponding respectively to another speed parameter of said motor vehicle, Vil being greater than Vi2; b) a plurality of measuring and calculating members for evaluating a quantity M of particles contained in said particle filter, an instantaneous speed Vs and another speed parameter Vi of said vehicle; and, c) a control member connected to said memory member and to said plurality of measuring and calculating members to cause the regeneration of said particle filter: - if a last regeneration has taken place more than a first predetermined period of time Al and, if M > Ml, Vs > Vsl and Vi > Vil; or, - if said last regeneration has taken place for more than a second predetermined period of time A2, A2 being greater than Al, and, if M > M2, Vs > Vs2 and Vi > Vi2. Said memory member records the instantaneous position and a foreseeable future course of said motor vehicle, while said plurality of measuring and calculating members evaluates, as a function of said instantaneous position and said foreseeable future course, said at least one other speed parameter Vi.

[0037] Such a device is easy to implement and requires only few structural modifications to the existing installation allowing the control and command of a thermal engine.

[0038] Preferably, the device comprises a first receiver to be able to capture the signals from a satellite positioning system adapted to provide said instantaneous position.

[0039] And according to a preferred embodiment, the device comprises a second receiver to be able to capture the signals of an advanced driving assistance system adapted to provide the instantaneous position and a predictable future course.

[0040] Other features and advantages of the invention will emerge from reading the description given below of particular embodiments of the invention, given for informational but non-limiting purposes, with reference to the appended drawings in which: [Fig.l] is a synoptic view of the implementation device according to the invention; and, [Fig.2] is a flowchart of the regeneration method according to the invention.

[0041] [Fig.l] shows a heat engine 10 of a diesel motor vehicle and a device 15 for implementing the method according to the invention.

[0042] The heat engine 10 has an exhaust duct 12 for the burnt gases, which extends to a metal casing 14 which contains a pollution control device including a particle filter 16. The metal casing 14 is of substantially cylindrical shape and it has two conical ends and an inlet 18 opposite an outlet 20.

[0043] According to the embodiment presented here, the inlet 18 of the housing 14 is equipped with an injector 22 making it possible to inject fuel inside the inlet 18.

[0044] The engine is controlled by means of an electronic control unit 24, which comprises a processor 26 and a database 28, and by means of sensors and actuators which will be described below.

[0045] Thus, the heat engine 10 is equipped with a first temperature sensor 30 for measuring the temperature of the engine coolant. The first temperature sensor 30 is directly connected to the processor 26. In addition, the heat engine 10 is equipped with a first pressure sensor 32, connected to the processor 26.

[0046] The housing 14 is equipped with a first second pressure sensor 34 located upstream of the particulate filter 16 and a second second pressure sensor 36 located downstream very close to the outlet 20. These two second pressure sensors 34, 36, connected to the processor 26, make it possible to establish a pressure difference between the inlet and the outlet. In addition, a flow meter 38 is installed at the outlet 20 to be able to measure the flow rate of the burnt gases at the outlet. The flow meter 38 is connected to the processor 26. In this way, it is possible to determine in real time and in a known manner from a map as a function of the pressure difference and said flow rate, the mass of particles contained in the particulate filter 16.

[0047] Furthermore, a second temperature sensor 40 is installed inside the housing 14 upstream of the particle filter 16. It is connected to the processor 16.

[0048] Also, the device 15 comprises a receiver 42 to be able to capture the signals from an advanced driving assistance system adapted to provide the instantaneous position and, in addition, a predictable future course of the motor vehicle in a driving situation. The receiver 42 is connected to the processor 26.

[0049] Preferably, the receiver 42 is not only equipped with a GPS receiver but also with an auxiliary reception device making it possible to capture relevant local cartographic information in real time.

[0050] The GPS receiver allows signals from a set of satellites to be captured to determine the position of the vehicle in real time. The auxiliary receiving device allows access, in particular, to the most probable route, the profiles of the traffic lanes, the maximum authorized speed or even information on intersections.

[0051] Such an auxiliary receiving device is part of a known driving assistance system, for example implemented through a standardized protocol of the ADASIS consortium, acronym for "Advanced Driver Assistance Systems Interface Specification". Thanks to this driving assistance system, it is possible to estimate the future course of the motor vehicle, with a horizon of at least the next eight kilometers. Other driving assistance systems can be implemented and for example through "Google Vehicle Map Service".

[0052] The method of regenerating the particle filter 16 according to the invention will now be described, not only with regard to [Fig. 1] but also to [Fig. 2] showing an operating flowchart.

[0053] First of all, in a first step 44, it is appropriate to record in the database 26, a certain number of threshold values ​​of the measured parameters.

[0054] In the example presented here, five calibrated states are defined, so as to be able to purge the particulate filter under the most favorable conditions possible. Purging the particulate filter consists of causing the combustion of the particles at high temperature, for example 650°C, by injecting fuel into the filter when it is itself- even already hot.

[0055] These calibrated states are: a very favorable state, a favorable state, a moderately favorable state, a less favorable state and a forced state.

[0056] Therefore, the operating program includes five decision steps, from most favorable to least favorable, during which it is verified that the values ​​of the measured parameters are greater than or less than thresholds.

[0057] Three parameters will have the same threshold values ​​for each of the five calibrated states.

[0058] Thus, threshold values ​​of the minimum temperature of the engine cooling water Teau_min and its maximum temperature Teau-max are recorded, as well as that of the minimum atmospheric pressure Patm_min. Recording this temperature and the atmospheric pressure makes it possible to ensure that the heat engine operates in optimal conditions.

[0059] Furthermore, to these three parameters will also be added a fourth parameter which will be monitored more simply directly through the processor 26 and this, in an equivalent manner for each of the five calibrated states, the predictable slope P of the traffic lane. The value of the slope must be zero or positive. This value, accessible thanks to the driving assistance system, in fact qualifies the future power required from the engine as will be explained below.

[0060] Furthermore, for each of the calibrated states, three particle mass thresholds of the filter are defined as a function of the kilometer distance D traveled since the previous regeneration of the particle filter.

[0061] Thus, three first particle mass thresholds are defined for the first state, a first very favorable mass threshold M_tfav_l if the distance traveled since the previous regeneration is less than 800 km, a second very favorable mass threshold M_tfav_2 if the distance traveled is between 800 km and 1000 km and a third very favorable mass threshold M_tfav3 if the distance traveled is greater than 1000 km. The thresholds of 800 km and 1000 km are here to be taken into account as non-limiting examples. Because in fact, other values ​​can be calibrated.

[0062] We define in the same way, and according to the same criteria: a first favorable mass threshold M_favl, a second favorable mass threshold M_fav2 and a third favorable mass threshold M_fav3; a first moderately favorable mass threshold M_mfavl, a second moderately favorable mass threshold M_mfav2 and a third moderately favorable mass threshold M_mfav3; a first less favorable mass threshold M_pfavl, a second less favorable mass threshold M_pfav2 and a third less favorable mass threshold M_pfav3; and, a first forced mass threshold M_forcél, a second forced mass threshold M_forcé2 and a third threshold of forced mass M_forced3.

[0063] Furthermore, for each of the calibrated states, the first mass threshold is greater than the second mass threshold which is itself greater than the third mass threshold. Also, M_tfavl< M_favl <M_mfavl<M_pfavl<M_forcél.

[0064] Furthermore, on each of the calibrated states, an instantaneous speed of the vehicle, a future minimum speed of the vehicle's travel and a future average speed are defined. The instantaneous speed can be given by means specific to the vehicles, for example by the rotational speed of the wheels, or by means of the GPS system.

[0065] As for the future minimum speed and the future average speed, they are given by the GPS receiver and the auxiliary receiving device and the driving assistance system.

[0066] It will be observed that the auxiliary reception device could draw this information from a file contained in the database 28, which file would be regularly updated.

[0067] Thus, at the level of the first calibrated state, we define a first very favorable instantaneous speed threshold V_tfav, a first very favorable average speed threshold tfav_moy and a first very favorable minimum speed threshold tfav_min.

[0068] At the level of the second calibrated state, a second favorable instantaneous speed threshold V_fav, a second favorable average speed threshold fav_moy and a second favorable minimum speed threshold fav_min are defined.

[0069] At the level of the third calibrated state, we define a third threshold of average favorable instantaneous speed V_mfav, a third threshold of average favorable average speed mfav_moy and a third threshold of average favorable minimum speed mfav_min.

[0070] At the level of the fourth calibrated state, we define a fourth threshold of unfavorable instantaneous speed V_pfav, a fourth threshold of unfavorable average speed pfav_moy and a fourth threshold of minimal unfavorable speed pfav_min.

[0071] And at the level of the fifth state, we define a forced instantaneous speed V_forced, a forced average speed forced_moy and a forced minimum speed forced_min.

[0072] Also, regarding the instantaneous speed V_tvaf > V_fav > V_mfav > V_pfav > F_forced; for the average speed, tfav_moy > fav_moy > mfav_moy > pfav_moy > forced_moy and, for the minimum speed, tfav_min > fav_min > mfav_min > pfav_min > forced_min. Indeed, as will be explained below, the method according to the invention aims to trigger the regeneration of the particle filter when the conditions are as favorable as possible. And this is the case when the speeds are the highest.

[0073] We also define for each of the calibrated states, a time Tps corresponding to the time elapsed since the last regeneration of the particle filter, and a temperature Tfap, corresponding to a temperature threshold of the inlet of the particle filter.

[0074] Thus, we define a very favorable time interval threshold, temps_tfav, : a favorable time interval threshold temps_fav, a moderately favorable time interval threshold temps_mfav, a less favorable time interval threshold temps_pfav and a forced time interval threshold temps_forced.

[0075] Also, temps_tfav < temps_fav < temps_mfav < temps_pfav < temps_forced. These conditions are intended to ensure that the regeneration of the particulate filter takes place at a low frequency. Because in fact, this regeneration consumes fuel.

[0076] In this way, we define a very favorable particle filter temperature tefap_tfav, a favorable temperature tefap_fav, a moderately favorable temperature tefap_mfav, a less favorable temperature tefap_pfav and a forced temperature tfap_forcé.

[0077] In the same way as for speed, tefap_tfav > tefap_fav > tefap_mfav > tefap_pfav > tefap_forced.

[0078] Thus, after all the threshold values ​​have been recorded, and when the motor vehicle is in a driving situation, the processor 26 takes into account all the values ​​of the measured variables: the distance D in kilometers of the motor vehicle measured since the last regeneration, the instantaneous speed Vs, the future average speed Vmoy and the minimum speed Vmin provided by the receiver 42, the time Tps which has elapsed since the last regeneration, the temperature of the particle filter Tfap given by the second temperature sensor 40, the water temperature Te of the engine cooling circuit given by the first temperature sensor 32, the atmospheric pressure Patm given by the first pressure sensor 30 and the average value of the future slope P obtained using the receiver 42.

[0079] The processor 26, according to a first conditional step 46, corresponding to the first calibrated state, then compares all the values ​​of the aforementioned measured variables corresponding respectively to the thresholds of the most favorable situation.

[0080] Thus, if for example the kilometric distance D traveled since the last regeneration of the particle filter is between 800 km and 1000 km, the processor then chooses a very favorable mass threshold M_tfav2, and the processor 26 checks whether this latter threshold is greater than the mass of particles in the particle filter measured using the two second pressure sensors 34, 36 and the flow meter 38.

[0081] Also, the processor 26 checks whether the instantaneous speed Vs, the predicted average speed Vmoy and the predicted minimum speed Vmin are respectively greater than the very favorable instantaneous speed threshold V_tfav, the very favorable average speed threshold tfav_moy and the very favorable minimum speed threshold tfav_min.

[0082] In addition, the processor 26 checks whether the time elapsed since the last regeneration of the particle filter Tps is greater than the very favorable time temps_tfav and whether the tem The particulate filter temperature is higher than the very favorable particulate filter temperature tefap_tfav.

[0083] The processor 26 also checks whether the engine cooling water temperature Te is between the minimum temperature Teau_min and the maximum temperature Teau_max and whether the measured atmospheric pressure Patm is greater than or equal to Patm_min.

[0084] Finally, the processor 26 checks whether the predicted slope P of the traffic lane over the next few kilometers, and at least the next eight kilometers, is greater than or equal to zero. This last condition is intended to verify that the engine power delivered to the wheel will be positive.

[0085] If all the above conditions are verified, then the regeneration step of the particulate filter 48 is triggered. To do this, the processor 26 controls the injector 22. In this way, a predefined quantity of fuel is injected through the particulate filter whose temperature is maximum. The combustion of the particles then takes place in an ideal situation where the efficiency is maximum and the injection of fuel through the filter is minimal.

[0086] If not, the processor 26, according to a second conditional step 50, corresponding to the second calibrated state, then compares all the values ​​of the aforementioned measured variables corresponding respectively to the thresholds of the favorable situation.

[0087] The conditions for triggering the regeneration of the particle filter are then significantly less favorable than those of the situation in which they are very favorable. Nevertheless, if all the conditions of the second conditional step 50 are all met, the regeneration of the particle filter is triggered by the processor 26.

[0088] If not, according to a third conditional step 52, the processor 26 then proceeds to compare all the values ​​of the aforementioned measured variables corresponding respectively to the thresholds of the moderately favorable situation. If they are all met, the regeneration according to step 48 is triggered by the processor 26. If one of them is not satisfied, the processor 26 then proceeds to compare, according to the fourth conditional step 54, all the values ​​of the aforementioned measured variables corresponding respectively to the thresholds of the unfavorable situation.

[0089] Again, if they are all met, regeneration according to step 48 is triggered. And if one of them is not satisfied, the processor 26 initiates the forced conditional step 56.

[0090] In this step 56, the threshold values ​​of the different variables are not very restrictive so as to be able to initiate the regeneration of the particle filter even in conditions which are unfavorable for the efficiency of the combustion of the particles and the associated fuel consumption.

[0091] If all these conditions are not met, the processor 26 issues a stop alert indicating that the particle filter is clogged and that it should be replaced.

Claims

Claims

1. Method for conditional regeneration of a particulate filter (16) of a motor vehicle with a thermal engine (10) in a driving situation, comprising the following steps: a) recording: - at least two first threshold values ​​Ml and M2, corresponding respectively to quantities of particles contained in said particulate filter (16), Ml being less than M2; - at least two second threshold values ​​Vsl and Vs2, corresponding respectively to instantaneous speeds of said motor vehicle, Vsl being greater than Vs2; - at least two third threshold values ​​Vil and Vi2, corresponding respectively to another speed parameter of said motor vehicle, Vil being greater than Vi2; b) evaluating, a quantity M of particles contained in said particulate filter (16), an instantaneous speed Vs and another speed parameter Vi of said vehicle;and, c) the regeneration of said particle filter (16) is caused: - if a last regeneration has taken place for more than a first predetermined period of time Al and, if M > Ml, Vs > Vsl and Vi > Vil; or, - if said last regeneration has taken place for more than a second predetermined period of time A2, A2 being greater than Al, and, if M > M2, Vs > Vs2 and Vi > Vi2, characterized in that in step a), the instantaneous position and the foreseeable future travel of said motor vehicle are recorded, and in step b), said at least one other speed parameter Vi is evaluated as a function of said instantaneous position and said foreseeable future travel;

2. Regeneration method according to claim 1, characterized in that said instantaneous position of said motor vehicle is recorded by capturing signals from a satellite positioning system.

3. A regeneration method according to claim 1 or 2, characterized in that said instantaneous position and said foreseeable future course are recorded by capturing signals from an advanced driver assistance system.

4. Regeneration method according to any one of claims 1 to 3, characterized in that said other speed parameter Vi corresponds to the average speed Vmoy evaluated as a function of said foreseeable future course and said instantaneous position.

5. Regeneration method according to any one of claims 1 to 4, characterized in that in step a) at least two fourth threshold values ​​Vj 1 and Vj2 are also recorded, corresponding respectively to minimum speeds, Vjl > Vj2, while in step b) a minimum speed Vmin is evaluated, and in that in step c) the regeneration of said particle filter (16) is caused: - if a last regeneration has taken place for more than said first predetermined period of time A1 and, if M>Ml, Vs>Vsl, Vi>Vil and if Vmin > Vj 1; or, - if said last regeneration has taken place for more than said second predetermined period of time A2, and, if M > M2, Vs > Vs2, Vi > Vi2 and if Vmin > Vj2.

6. Regeneration method according to any one of claims 1 to 5, characterized in that in step a) at least two fifth threshold values ​​T1 and T2 are also recorded, corresponding respectively to particle filter inlet temperatures (16), T1 > T2, while in step b) the temperature T at the inlet of said particle filter is evaluated, and in that in step c) the regeneration of said particle filter is caused: - if a last regeneration has taken place for more than said first predetermined period of time A1 and, if M>M1, Vs>Vs1, Vi>Vil and if T > T1; or, - if said last regeneration has taken place for more than said second predetermined period of time A2, and, if M > M2, Vs > Vs2, Vi > Vi2 and if T > T2.

7. Regeneration method according to any one of claims 1 to 6, characterized in that in step b), the average slope P of said stroke is further evaluated as a function of said foreseeable future stroke and said instantaneous position, and in that in step c) the regeneration of said particle filter is caused if, in addition, said average slope is greater than or equal to zero.

8. Device (15) for implementing the method of conditional regeneration of a particle filter (16) of a motor vehicle with a thermal engine (10) in a driving situation, according to any one of claims 1 to 7, said device comprising: a) a memory member (28) for recording:

9.

10. - at least two first threshold values ​​Ml and M2, corresponding respectively to quantities of particles contained in said particle filter, Ml being less than M2; - at least two second threshold values ​​Vsl and Vs2, corresponding respectively to instantaneous speeds of said motor vehicle, Vsl being greater than Vs2; - at least two third threshold values ​​Vil and Vi2, corresponding respectively to another speed parameter of said motor vehicle, Vil being greater than Vi2; b) a plurality of measuring and calculating members (34, 36, 38, 42) for evaluating a quantity M of particles contained in said particle filter (16), an instantaneous speed Vs and another speed parameter Vi of said vehicle; and, c) a control member (26) connected to said memory member (28) and to said plurality of measuring and calculating members (34, 36, 38, 42) to cause the regeneration of said particle filter (16): - if a last regeneration has taken place more than a first predetermined period of time Al and, if M > Ml, Vs > Vsl and Vi > Vil; or, - if said last regeneration has taken place for more than a second predetermined period of time A2, A2 being greater than Al, and, if M > M2, Vs > Vs2 and Vi > Vi2, characterized in that said memory member records the instantaneous position and a foreseeable future travel of said motor vehicle, while said plurality of measuring and calculating members evaluates, as a function of said instantaneous position and said foreseeable future travel, said at least one other speed parameter Vi. Device according to claim 8, characterized in that it comprises a first receiver to be able to capture the signals from a satellite positioning system adapted to provide said instantaneous position. Device according to claim 8 or 9, characterized in that it comprises a second receiver (42) to be able to capture the signals of an advanced driving assistance system adapted to provide the instantaneous position and a predictable future course.

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