FR2931876A1 - Fuel quantity regulating device for regenerating particle filter in diesel type motor vehicle, has control unit with flow rate correction module multiplying determined quantity of fuel by function of gas flow rate in inlet of catalyst - Google Patents

Abstract

The device has an electronic control unit (9) for determining quantity of fuel to be injected for regenerating a particle filter in an exhaust line (6) based on an operating point of an internal combustion engine of a motor vehicle. An estimation unit estimates flow rate of gas in an inlet of an oxidation catalyst, and is connected to the control unit. The control unit has a flow rate correction module (39) multiplying the determined quantity of fuel by a function of gas flow rate in the inlet of the catalyst. An independent claim is also included for a method for regulating quantity of fuel to be injected for regenerating a particle filter in an exhaust line of a motor vehicle.

Description

PATENT APPLICATION B08 / 0717FR ODE / JK Simplified joint stock company known as: RENAULT s.a.s Device and method for regulating the regeneration phases of a particle filter for a combustion engine. Invention of: TURPIN Thomas SADAI Stephane BUREL Gael Device and method for regulating the regeneration phases of a particulate filter for a combustion engine.

The present invention is in the field of exhaust gas treatment of internal combustion engines for a motor vehicle of the diesel type. The invention relates more particularly to the regulation of the amount of fuel to be used to allow a temperature rise of the gases arriving at a particulate filter through an oxidation catalyst, and to proceed with the regeneration of this filter by combustion of the particles trapped therein. In order to meet the lowering of the permissible thresholds for the emission of gaseous pollutants from motor vehicles, exhaust aftertreatment systems arranged in the exhaust line of the engines are generally provided. These after-treatment systems make it possible in particular to reduce particulate and nitrogen oxide emissions as well as carbon monoxide and unburned hydrocarbons. These post-processing systems operate discontinuously for specified periods. In normal operation, the systems trap pollutants but only treat them during so-called regeneration phases. To be regenerated, a post-treatment system comprising a particulate filter requires a combustion mode specific to the internal combustion engine to ensure a suitable temperature and / or wealth level. Diesel combustion engines, because of their specific operation, emit in their exhaust gases larger quantities of soot pollutants that are usually called particles. In order to limit the emissions of these particles into the atmosphere, a filter is placed in the exhaust line of the combustion engine downstream of the combustion chambers of the engine. This filter retains the soot particles that accumulate within it as the engine is used. Internal combustion engines also emit reducing pollutants such as HC, CO, etc. In the presence of oxygen and catalytic materials such as for example platinum, and at high temperature, these reducing pollutants can be oxidized. In order to obtain this oxidation, an oxidation catalyst device is generally present in the exhaust line upstream of the particulate filter. It is also possible to design a so-called catalytic particulate filter which comprises within it a catalytic material producing this oxidation. The accumulation of soot particles in the filter eventually closes it creating a strong counter pressure to the engine exhaust, which significantly reduces its performance. In order to regain the normal performance of the engine, periodically the particle filter is regenerated. This regeneration is carried out by increasing the temperature of the gases arriving at the particle filter, which results in the initialization and maintenance of the combustion of the particles trapped in the filter.

To obtain such a rise in temperature, for example, a delayed injection of fuel into the combustion chambers of the engine is carried out. Fuel is then injected after the top dead center during the expansion phase which has the effect of increasing the temperature of the exhaust gas. The fuel thus injected does not burn in the combustion chamber, but subsequently oxidizes in the exhaust line or at the level of the catalyst. It is also possible to inject the fuel directly into the exhaust line in order to enrich the exhaust gases with reducing products, resulting from a first fractionation of the fuel injected under the effect of heat.

Oxidation, either in the exhaust line or in the catalyst, of the reducing products contained in the exhaust gases such as HC and CO, increases the temperature of the gases arriving at the particulate filter. It is thus possible to obtain the rise in temperature necessary for the initiation of the regeneration reaction of the particulate filter.

However, if the temperature becomes too high, the catalytic particles, for example platinum, may then agglutinate and reduce the contact area with the exhaust gas, and thus the performance of the catalyst. If the temperature is very high, the ceramic materials that are generally used to support the catalytic materials can collapse, creating cracks in the catalyst. In addition, avoid sending a surplus of fractionated hydrocarbons to the catalyst that could not be completely oxidized, so as not to generate polluting species (HC, CO) beyond the regulatory thresholds. The regeneration operation of the particulate filter is carried out periodically as soon as a quantity of particles in the filter is detected which is too large. This detection can be obtained for example by a measurement of differential pressure upstream and downstream of the particle filter or by any other appropriate means. The regeneration operation is performed when the vehicle engine is running and must not be discernible by the driver and passengers of the vehicle. To avoid excessive temperature rises and control the regeneration phase, the amount of fuel injected for regeneration is generally regulated as a function of the outlet temperature of the catalyst, which is at the same time the inlet temperature of the catalyst. particle filter. The French patent application 2,864,992 (BOSCH) describes such a regulation of the quantity of fuel injected during the regeneration phases from the difference between the temperature at the outlet of the catalyst and a set value, and also as a function of the difference between the temperature upstream of the catalyst and a set value, to improve the regulation taking into account the inertia of the catalyst. German patent application DE 100 33 159 (Daimler Chrysler) proposes a regulating device comprising two control loops, the fuel for the regeneration being injected by post-injection into the cylinders of the engine. The first loop regulates the post-injected fuel flow using, as input quantity, the temperature downstream of the catalyst. The second regulation loop regulates the moment of the fuel injection by using as input quantity the temperature measured by a sensor upstream of the catalyst. The French patent application no. 0654519 in the name of the Applicant, unpublished, proposes to improve the response dynamics of the temperature regulation of the gases arriving at the particle filter, by adding a PID type regulation to a set temperature, and a correction representative of the temperature evolution dynamics of the catalyst, resulting from a mapping. However, this map is extracted from the known operating modes of the system in stabilized mode, which may have deviations from the transient modes of operation. None of these control methods can satisfactorily take into account the dynamics of the reactions that take place in the catalyst and the mass-related inertia of the latter during the transient phases of engine operation. In particular, variations in gas flow rates in the exhaust line are likely to modify the stoichiometry of the species involved, and their taking into account through the temperature is not sufficient to avoid the production of unburnt hydrocarbons incompletely oxidized in the catalyst. The present invention aims to improve the control performance of the amount of fuel injected for the regeneration of the particulate filter so as to best account for the transient phases of engine operation.

The subject of the invention is a device for regulating a quantity of fuel to be injected for the regeneration of a particulate filter of an exhaust line of a motor vehicle, an exhaust line comprising an oxidation catalyst. and a particulate filter mounted downstream of the catalyst. The device comprises a control unit able to determine the amount of fuel to be injected for the regeneration of the particulate filter depending on the operating point of the vehicle engine. The device further comprises means for estimating the catalyst gas flow rate, connected to the control unit. The control unit comprises a correction module capable of multiplying the quantity of fuel determined previously by the control unit, by a function of said gas flow rate at the inlet of the catalyst. In a preferred embodiment, the correction module comprises a map of values of the catalyst inlet gas flow rate as a function of the operating point of the engine and in steady state of the engine, and the correction module is configured to multiply the amount of fuel. determined by the control unit by the ratio of the gas flow estimated at the inlet of the catalyst, and the gas flow from the mapping.

In another preferred embodiment, the correction module comprises a first mapping of values of the gas flow rate at the inlet of the catalyst, as a function of the operating point of the engine and in steady state of the engine, and comprises maps of pairs of values of threshold depending on the operating point of the engine, and the correction module is configured to multiply said quantity of fuel determined by the control unit, by the ratio of the estimated gas flow rate at the inlet of the catalyst, and the flow rate of gas from the first mapping, said report being limited by the threshold values from the second maps.

Advantageously, the device may comprise a temperature sensor at the inlet of the particulate filter, and the control unit may comprise a regulator of the Proportional Integral Derivative (PID) type which generates a correction of the value of the quantity of fuel to be injected, from the difference between the temperature measured by said input sensor of the particulate filter and a set temperature. Another aspect of the invention relates to a method for regulating a quantity of fuel to be injected for the regeneration of a particulate filter mounted in the exhaust line of a vehicle engine downstream of a catalytic converter. oxidation, wherein the amount of fuel to be injected is calculated from the sum of a closed-loop control, and an open-loop control. In the closed-loop control, a measured temperature is compared with a set temperature. The open loop control is calculated from one or more maps of operating values of the vehicle exhaust line, in steady state of the engine and according to the operating point of the engine. The value of the open-loop control is weighted by a function of the value of the catalyst inlet gas flow before being added to the value of the closed-loop control.

In a preferred embodiment of the method, the value of the open-loop control is multiplied, before summation, by the quotient of the value of the estimated gas flow rate at the inlet of the catalyst, and a value of the gas flow rate from a mapping function of the operating point of the engine, said quotient being bounded by two threshold values, also functions of the operating point of the engine. Advantageously, the value of the closed-loop control is calculated using a Proportional Integral Derivative-type controller. In an alternative embodiment of the method, the control of the quantity of fuel to be injected for the regeneration of the particle filter is calculated by carrying out the following steps: - it is determined, according to the operating point of the engine, to the using a cartography, a first value of quantity of fuel to be injected; to this first value is added one or more fuel quantity corrections to be injected, said corrections being calculated using an estimated temperature value at the inlet of the catalyst and using operational mappings of the line; vehicle exhaust; the value thus corrected is multiplied by a function of the gas flow rate at the inlet of the catalyst; - The previous result is added a correction value from a closed control loop loop that compares a measured temperature and a set temperature using a Proportional Integral Derivative (PID) type regulator. Advantageously, the operation maps of the exhaust line are used to estimate the values that should be present, in steady state of the engine, for the current operating point of the engine, one or more of the following variables: the temperature at the input of the catalyst, - the temperature gain between the inlet and the outlet of the catalyst, - the response time or the rate of variation of the temperature gain between the inlet and the outlet of the catalyst, - the ratio between the quantity of fuel injected for the regeneration and the temperature at the exit of the catalyst, the response time or the speed of variation of the ratio between the quantity of fuel injected for the regeneration and the temperature at the outlet of the catalyst. Preferably, the values derived from the preceding maps are used by a dynamic adjustment module to predict the evolution of the temperature of the gases leaving the catalyst. Thanks to these mappings, a point temperature measurement at the inlet of the catalyst enables the dynamic adjustment module to predict, more rapidly than the evolution of these temperatures can not be measured by a sensor, the evolution of the inlet temperature, as well as that the evolution of the temperature at the outlet of the catalyst. The invention will be better understood from the study of an embodiment taken by way of nonlimiting example illustrated by the accompanying drawings in which: - Figure 1 shows schematically the exhaust line of an internal combustion engine ; FIG. 2 illustrates the main elements of a control unit used in the regulation according to the invention. - Figure 3 shows an embodiment of the dynamic adjustment module of Figure 2. As shown in Figure 1, the internal combustion engine 1, shown very schematically, is a four-cylinder diesel engine. The combustion chambers of the engine shown diagrammatically and referenced 2 are supplied with compressed air via an intake duct 3. The admitted fresh air is compressed by a turbo compressor 4 whose compressor is rotated by a turbine traversed by the exhaust gas from the exhaust pipe 5. At the turbine outlet, the exhaust gas is conveyed by an exhaust line 6 which comprises a catalyst device 7 followed by a particulate filter (FAP) 8 Although in this example, the catalyst has been shown in the form of a device separate from the particulate filter, it will be understood that the two devices could be juxtaposed, or that the catalytic materials could be arranged inside the filter itself. particulate matter without major modification of the present invention. An ECU electronic control unit, referenced 9, controls the operation of the engine 1 and also allows the control of the regeneration of the particle filter 8. For this purpose, the electronic control unit 9, which receives various parameter information of operation of the motor through the connections 10, is capable of transmitting a control signal through the connection 11 for the purpose of injection into the exhaust line, by a specific injector 12 called "fifth injector", of a certain amount of fuel so as to increase the amount of unburned fuel and the temperature of the exhaust gas for a regeneration phase of the particulate filter. FIG. 1 also shows various sensors, and in particular a differential pressure sensor 14 measuring the difference in gas pressure between the inlet and the outlet of the particulate filter 8, by means of a stitching of pressure 20 located upstream of the particulate filter 8 and a pressure tap 21 located downstream of the particle filter 8. The connection 15 brings the differential pressure signal emitted by the sensor 14 to the electronic control unit 9. Such a differential pressure measurement makes it possible to detect the moment when the particle filter is loaded with soot particles in such a way that a regeneration phase must be initiated. In Figure 1, there is also shown a temperature sensor 16 which determines the temperature at the outlet of the catalyst 7, which is also the TeFAP inlet temperature of the particulate filter. A second temperature sensor 17 determines the temperature upstream of the catalyst 7 is Tamont. These temperatures are brought by the connections 18 and 19 to the electronic control unit 9. In a variant, the temperature sensor 17 may for example be replaced by a temperature sensor placed upstream of the turbine of the turbo compressor 4, which determines a TavTurb temperature whose electronic unit deduces the temperature Tamont using a suitable calculation model.

A flowmeter 22 at the outlet of the compressor makes it possible to measure the flow rate of compressed air sent into the engine, the value of which is supplied via the connection 23 to the electronic control unit 9. The main elements of the regulation are illustrated in FIG. FIG. 2 shows the same elements bearing the same references and in particular the exhaust line 6 comprising the different temperature sensors 16, 17, the fifth injector 12 and its connection 11, as well as the connections 10 and 23 of the control unit 9 bringing him the engine parameters and the air flow at the engine inlet. The control unit 9 includes a prepositioning module 36, which delivers a fuel quantity value to inject InjPrepos for the regeneration of the particulate filter. The prepositioning module has a memorized map 35 of quantities of fuel to be injected as a function of the operating point of the engine. The operating point of the motor is shown schematically in the figure by the pair of values N, C, sent by the connections 10 to the control unit 9, N being the rotational speed of the engine and C the engine torque. The prepositioning module compares the engine operating point with the map 35, and delivers a value of fuel quantity to be injected. This prepositioning module 36 can be completed by a dynamic adjustment module 34 which adds a corrective term AlnjDynam to the value derived from the mapping 35. This correction term is calculated on the basis of the evaluation of a probable speed of temperature evolution of the catalyst. The prepositioning module thus outputs an IniPrepos value of fuel quantity to be injected, which is, according to the variant embodiments, derived from the single mapping 35, or is the sum of the value resulting from the mapping 35 and the corrective term AlnjDynam . The control unit 9 also comprises a flow correction module 39 which delivers a correction coefficient CoeffQ, which is a function of the flow rate of gas Qgaz through the catalyst, and the operating point of the engine. The operating point of the motor is shown schematically by the values N, C supplied to the module by the connections 10. The flow correction module 39 receives via the connection 23 the value of air flow entering the engine. From the operating point of the engine and the quantity of fuel injected at each instant, the module 39 deduces the flow of Qgaz gas passing through the catalyst. The module 39 also has three stored maps, all three depending on the operating point of the engine. The first mapping 40 gives, according to the operating point of the engine, a QgazRef gas flow rate, referred to as the reference gas flow rate, which corresponds to the flow rate entering the catalyst for the same operating point of the engine, but in steady state stabilized motor. In transient conditions in particular, the mapped value QgazRef is generally different from the value Qgaz measured or deduced from measurements. The module 39 performs the quotient of the flow measurement value Qgaz, by the flow rate value QgazRef extracted from the map 40. The two other maps 41 and 42 arbitrarily assign, at each operating point of the engine, two threshold values. dimensionless Qmin and Qmax, Qmin being less than Qmax. The module 39 checks whether the coeffQ value is between the Qmin and Qmax terminals extracted from the maps 41 and 42. If coeffQ is lower, it substitutes the value Qmin. If coeffQ is greater, it substitutes for it Qmax. The coeffO value thus obtained is then sent via a connection to a multiplier 43. The thresholding can of course be done directly equivalent to the Qgaz value, by means of two mappings of threshold values each having the dimension of a debit. It is also possible, according to an alternative embodiment, to measure a flow of gas Qentrée elsewhere than at the inlet of the engine, for example at the level of the exhaust line. It is also possible to apply the preceding process either by recalculating the Qgaz gas flow rate at the inlet of the catalyst, as described, or by choosing to define reference gas flow rates so that said QgazRef reference flows are defined at the same time. where is measured the current flow Q input. It is then possible to use the measured input value directly to calculate the ratio coeffQ = Qentrance / QgazRef.

The flow correction module 39 comprises a multiplier 43 on a branch from which the fuel quantity value InjPrepos arrives from the prepositioning module 36. The correction module sends the corrective coefficient coeff (Q) on another branch of the multiplier 43. The module flow correction 39 thus delivers to the output of the multiplier 43 an amount of fuel IniDébit which is the product of InjPrépos CoeffQ coefficient, and which takes into account the operating point of the engine, the actual flow rate of gas passing through the catalyst, and, by the correction of the dynamic adjustment module 34, the dynamic evolution in temperature of the catalyst. The connections 10 supplying the values N, C of the operating point of the motor, the connection 23 bringing the value of the incoming air flow rate, the prepositioning module 36, the rate correction module 39 and the connections to the multiplier 43 constitute a loop. 44, whose inputs include N, C, the incoming air flow Qentrée, and output a quantity of fuel to inject InjDébit. In order to take into account production dispersions that can not be comprehensively taken into account by the maps used in the open loop 44, the control unit also comprises a closed control loop 37 comprising a regulator 38, which is here given for example, a regulator of the proportional integral derivative type (PID). The regulated quantity is, for example, the difference c which is fed to the input of the regulator 38 and which corresponds to the difference between a setpoint temperature TeFAPset and the temperature TeFAP measured at the outlet of the catalyst. The control unit adds the regulation value AIniPID delivered by the regulator 38, and the fuel quantity value InjDebbit delivered by the open loop, to obtain the fuel quantity control Inn finally sent to the fifth injector via the connection 11. FIG. 3 illustrates an exemplary embodiment of a dynamic adjustment module 34. A memorized map 24 as a function of the engine rotation speed denoted N and the engine torque denoted C provides a temperature value upstream of the catalyst device Tamont under steady state conditions. for different operating points of the motor. This expected value resulting from the mapping 24 is brought to the negative input of a comparator 25. The comparator 25 also receives on its positive input the upstream temperature Tamont as measured by the sensor 17. The comparator 25 thus establishes a gap ATamont relative to the operating point of the engine in steady state. In order also to take into account the thermal inertia of the catalyst device 7 and the exothermic catalytic reactions which increase the temperature of the exhaust gases passing through the catalyst 7, a gain is applied to the first correction thus obtained. For this purpose, the correction module 22 comprises a map 26, this map giving for each operating point of the engine in steady state the value of a gain K1 which corresponds to the ratio between the outlet temperature of the catalyst device 7 TeFAP at the temperature upstream of the catalyst 7 Tamont is: K1 = TeFAP Tamont The value of this gain is further filtered in the filter 27 noted F1 by means of a response time ti which reflects the rate of change of this gain for a mode stabilized operation of the engine. This response time ti is determined as a function of the operating point of the engine by a map 28. The processing module 29 combines the dynamic gain sent by the filter 27 and the deviation at the steady state of Tamont sent by the comparator 25, for to deliver a dynamic temperature difference ATeFAP at the outlet of the catalyst. The dynamic adjustment module 34 further comprises means for establishing a correction on the quantity of fuel to be injected to reach the target temperature TeFAPeign. For this purpose, a map 30 makes it possible to determine a second gain K2 as a function of the operating point of the engine. The value of this gain K2 corresponds to the quantity of fuel injected Inn divided by the value of the outlet temperature TeFAP of the catalyst is: K2 = Inj TeFAP. This gain is filtered in the filter 31 noted F2 by means of a response time t2 of the catalyst device 7, determined according to the operating point of the engine in steady state by means of a map 32. The response time t2 resulting from this mapping is brought to the input of the filter 31 so as to obtain a filtered gain which is fed to a processing module 33 also receiving the correction relating to the outlet temperature of the catalyst device.

The processing module 33 then determines the AlnjDynam correction value to be applied to the quantity InjPrepos of fuel to be injected. It will be noted that the gains K1 and K2 and the response times t1 and t2 all come from mappings established under steady-state engine conditions. The dynamic adjustment module 34 thus makes it possible to use the knowledge of the evolution dynamics of the catalyst in steady state of the engine in order to propose, for the quantity of fuel to be injected, a quicker adjustment than that obtained by the control loop. closed control 37. Indeed, the dynamic adjustment module 34 estimates and anticipates the imminent evolution of the system temperatures, while the PID loop 37 only shows it, undergoing both the inertia of the catalyst and that of the sensors. On the other hand, the closed loop 44 makes it possible to correct the more constant deviations linked, for example, to manufacturing deviations between the vehicle used to establish the maps and the vehicle equipped with the system according to the invention. The prepositioning map 35 and the mappings from which K1, K2, t1 and t2 are deduced represent a particular mode of operation of the engine in steady state, with the flow of exhaust gas associated therewith. However, for the same operating point of the engine defined by a speed and a torque of the engine, this gas flow can vary for example depending on the driving conditions, the outside temperature, the atmospheric pressure. In addition, this flow will be different if the same operating point of the engine corresponds to a transient mode.

Thanks to the flow correction module 39, the invention makes it possible to compensate for this variability of the engine and of the exhaust line, by a correction with a low response time, correction directly related to the stoichiometry of the oxidation reactions that the we try to drive in the catalyst. The invention makes it possible to obtain better control of the temperature at the outlet of the catalyst device during the transient modes, corresponding for example to large variations of the motor parameters during relatively short time intervals.

It also allows an adjustment of this temperature control for operating conditions that deviate from the conditions used to establish fuel quantity maps to inject a priori based on the operating point of the engine.

Claims (8)

REVENDICATIONS1. Device for regulating a quantity of fuel to be injected for the regeneration of a particulate filter of an exhaust line (6) of a motor vehicle comprising an oxidation catalyst (7) and a particulate filter ( 8) mounted downstream of the catalyst, said device comprising a control unit (9) able to determine the quantity of fuel to be injected for the regeneration of the particulate filter according to the operating point of the engine of the vehicle, characterized in that it further comprises means (22) for estimating the gas flow rate at the inlet of the catalyst, connected to the control unit (9), and in that the control unit comprises a correction module (39) suitable for multiplying the amount of fuel previously determined by the control unit by a function (CoeffQ) of said gas flow at the inlet of the catalyst. 2. Control device according to claim 1, wherein the corrector module (39) comprises a map (40) of values of the gas flow rate at the inlet of the catalyst as a function of the operating point of the engine and in steady state of the engine, and wherein the correction module is configured to multiply the quantity of fuel (Inprespos) determined by the control unit by the ratio of the estimated gas flow rate at the inlet of the catalyst (Qgaz), and the gas flow rate (QgazRef) from the mapping. 3. Control device according to claim 1, wherein the corrector module (39) comprises a first map (40) of values of the gas flow rate at the inlet of the catalyst, as a function of the operating point of the engine and in steady state of the engine. , and comprises maps (41, 42) of threshold value pairs as a function of the operating point of the engine, and wherein the correction module is configured to multiply said fuel quantity (Iniprépos) determined by the control unit, by the ratio of the gas flow estimated at the inlet of the catalyst (Qgaz), and the gas flow rate (QgazRef) resulting from the first mapping (40), said ratio (coeffQ) being limited by the threshold values resulting from the second mappings ( 41,42). A control device as claimed in any one of the preceding claims, further comprising a temperature sensor (16) input to the particulate filter (8), and wherein the control unit comprises a regulator (38) of the type Proportional Integral Derivative (PID) which generates a correction (AIäiPJD) of the value of fuel quantity to be injected, from the difference between the measured temperature (TeFAP) by said sensor (16) at the inlet of the particulate filter and a temperature setpoint (TeFAPeign). 5. A method of regulating a quantity of fuel to be injected for the regeneration of a particulate filter (8) mounted in the exhaust line of a vehicle engine downstream of an oxidation catalyst (7) wherein the amount of fuel to be injected (Inn) is calculated from the sum of a closed-loop control (37), in which a measured temperature (TeFAP) and a target temperature (TeFAPcOnsign) are compared, and an open loop control (44), calculated from one or more maps (35, 24, 28, 30, 32) of operating values of the vehicle exhaust line, in steady state of the engine and according to the operating point of the engine, characterized in that the value of the open-loop control (Inprespos) is weighted by a function (coeff ()) of the value of the catalyst inlet gas flow before being added to the value (AIniPID) of the closed-loop control (44). 6. Method according to the preceding claim, wherein the value of the open loop command (IniPrepos) is multiplied, before summation, by the quotient of the value of the estimated gas flow rate at the inlet of the catalyst (Qgaz), and a gas flow value (QgazRef) derived from a mapping function of the operating point of the engine, said quotient being bounded by two threshold values (Qmin, Qmax), also functions of the operating point of the engine. 7. Control method according to the preceding claim, wherein the value of the closed-loop control is calculated using a regulator (38) of Proportional Integral Derivative (PID) type. 8. Control method according to any one of claims 5 to 7, wherein, during the calculation of the control of the amount of fuel to be injected for the regeneration of the particle filter: - is determined, depending on the point of operating the engine, using a map (35), a first fuel quantity value to be injected; one or more corrections (AlnjDyäam) of quantity of fuel to be injected are added to this first value, said corrections being calculated using an estimated value (Tamont) of temperature at the inlet of the catalyst and using mappings; operating values of the vehicle exhaust line (24, 26, 28, 30); the value thus corrected is multiplied by a function (CoeffQ) of the gas flow rate at the inlet of the catalyst; a correction value is added from a closed control loop comparing a measured temperature and a set temperature using a regulator (38) of Proportional Integral Derivative (PID) type.