FR2976321A1 - METHOD AND DEVICE FOR DIAGNOSING AN INTERNAL COMBUSTION ENGINE PARTICLE FILTER - Google Patents

Abstract

A method of diagnosing an exhaust gas channel particle filter (42) (30) of an engine (10) by predicting as a charge particulate filter (42) the charge (131) obtained at using a particle sensor (45) from difference measurements and / or a charge pattern of carbon black. From the result, a regeneration of the filter (42) is started. The result of the diagnosis of the filter (42) is validated as to its ability to function from a relation between the charge of the particulate filter (131) and the volume flow rate of the exhaust gas (46) in the gas channel. exhaust (30) or the volume flow gradient of the exhaust gas (46). Based on this validation, the particle filter (42) is classified as operable or defective.

Description

FIELD OF THE INVENTION The present invention relates to a method for diagnosing a particulate filter installed in the duct. Exhaust gases from an internal combustion engine are conducted according to which it is prone to charge black. Particle filter smoke, Particle filter charge obtained using a particle sensor, from difference measurements and / or a charge pattern, and from the result from the diagnosis, an operation of regeneration of the particle filter is started. The invention also relates to a device applying such a diagnostic method. STATE OF THE ART Often the internal combustion engines, in particular the diesel engines and, in the future, probably also the gasoline direct injection engines, will be equipped with an exhaust aftertreatment system comprising in particular a particulate filter. The particulate filter clogs up with black smoke (particles) during engine operation and must be regenerated at defined intervals. For this purpose control and control facilities are required which manage the regeneration of the particulate filter. This functionality can be divided into three basic functional blocks: - the evaluation of the blackflame charge in the particulate filter, the control / control of the active regeneration, and the coordination of the regeneration in the different operating phases of the internal combustion engine. The purpose of this last function block is to start regeneration as quickly as possible when a certain level of smoke charge is reached or exceeded. But this must be done under the most advantageous operating conditions of the internal combustion engine. The active re-generation control / command function block comprises all the control means equipping the internal combustion engine and allowing the oxidation of the black-smoke particles accumulated in the filter. This operation is performed

2 periodically to remove the carbon black from the particulate filter by burning it. The particle sensor (PM sensor) is used to monitor the operation of particulate filters. Resistance particle collector sensors are known which exploit a variation in the electrical characteristics of an interdigitated electrode (IDE) structure based on particle accumulation. When the particle sensor is fully charged, the accumulated particles are burned during a regeneration phase by means of a heating element integrated in the particle sensor. Such a resistance particle sensor is, for example, described in DE 201 13 384 A1. The maximum charge of black smoke of the particle filter depends decisively on the material constituting the substance of the filter such as porosity, cell density and channel geometry and in particular the melting temperature as well as the heat capacity. The release of heat during the regeneration is proportional to the carbon black charge contained in the particulate filter and this release is decisively responsible for the maximum temperature in the particulate filter. Conventional regeneration strategies applied for example to a diesel engine use special injection profiles and air flows so as to achieve a higher temperature in the exhaust gas channel of the internal combustion engine and oxidize the lampblack. For this, a large number of measurements are taken because the high temperatures required for the exhaust gases, which range from 600 ° C. to 650 ° C., are reached during normal operation of the diesel engine only when the latter is operating near the engine. full charge. In particular, in the case of low engine loads and 30 rotational speeds, in addition to actions on the air supply system (throttle flap), it is necessary to intervene in the injection to regulate the flow. temperature range evoked above. These are, for example, measures consisting of delaying the main injected quantity (MI), delivering a post-injection (Po12) into the combustion engine or delivering a hot (Poli) post-injection into the catalyst.

3 Diesel Oxidation (DOC). This requires a certain amount of residual oxygen in the exhaust gas to allow this oxidation. For example, document EP 1 364 110 B1 discloses a method and a device for controlling an internal combustion engine with a particulate filter in the exhaust aftertreatment system for which an operation is provided. of regeneration to reduce the charge of the particulate filter. In this operation, the characteristic quantity (temperature of the filter TF) of the internal combustion engine is determined according to at least one operating parameter (speed of rotation / speed N, quantity of fuel injected QK, quantity of sucked air ML and / or oxygen concentration 02) and at least one operating parameter (combustion rate AV, sucked air mass ML, exhaust gas temperature TA and / or charge state DP) of the particulate filter characterizing the the future intensity of the reaction in the particulate filter. It is expected that if a threshold is exceeded by the characteristic value TF, at least one measure is taken to reduce the oxygen concentration in the combustion gases emitted by the internal combustion engine so that the characteristic quantity TF reaches the threshold. The duration of the regeneration depends on the rate of oxidation of the lampblack and the amount of lampblack contained in the particulate filter. The main influence coefficients for the oxidation rate are the oxygen content and the substrate temperature of the particulate filter. As the regulation of permissible particulate emissions becomes more stringent, to meet future exhaust standards, it will no longer be possible to diagnose the reduction of the efficiency of a particulate filter using 30 of a pressure difference sensor. With the aid of a PM sensor, it is possible to detect a small reduction in the efficiency of the particulate filter. However, the signal behavior provided by the PM sensor depends on the state of charge of the damaged particle filter and the very high rate of exhaust volume or gradient flow in the volume flow rate. This is why the pattern of signal behavior

4 of the PM sensor is corrected according to a field of characteristics depending on the load and the volume flow. Since the diagnostic accuracy of a PM sensor depends on the load, this accuracy is deteriorated by the following causes: the state of charge of the particulate filter is an evaluated value which can be very imprecise, the influence the particulate filter load and the exhaust gas flow rate depend on the deterioration state of the particulate filter; this state of the particulate filter may, however, be very different so that the influence of the dependence of the load itself depends on the state of deterioration. The following risks may be present at the time of diagnosis: a particulate filter in order (particle filter at most slightly damaged with a particle emission below the OBD limit) is recognized as defective, which corresponds to the non-compliant recording. A defect, or a defective particle filter (a damaged particulate filter with particle emission greater than or equal to the OBD limit) is recognized as being in order (evaluation error). Under these circumstances, currently in an extreme case, the exhaust gas cleaning system can be applied as an OBD non-compliant, which carries the risk of an authorization withdrawal. In addition, the reliability of the diagnosis also depends on the driving state (for example urban traffic or motorway traffic) because the degree of deposition of a particle filter limit model, that is to say of a damaged particle filter with a particle emission just below the OBD limit and thus the PM sensor signal also depends on the particle filter load and the exhaust gas volume flow rate. OBJECT OF THE INVENTION The present invention aims to improve the accuracy and reliability of the diagnostic process to avoid the risks mentioned above. The invention also aims to develop a device for implementing such a method. DESCRIPTION AND ADVANTAGES OF THE INVENTION For this purpose, the subject of the invention is a process characterized in that a validation of the result of the diagnosis of the particulate filter is made with regard to its ability to function from a relationship between the particle filter charge and a volume flow rate of exhaust gas in the exhaust gas channel or a gradient of the volume flow of the exhaust gas and according to this validation, the particle filter is classified as able to function or as defective or the result of the diagnosis of the particle filter is considered as not being able to be exploited. The method according to the invention allows a safe, reliable and robust diagnosis to meet the requirements of the on-board diagnostic reliability regulation, particularly in the case of diesel engines. This applies in particular to the regulation in the United States as well as the reinforcement of the standard relating to exhaust gases in the European Union (Euro 6). This leads to minimizing the risk of erroneous authorization diagnosis and thus lowering the costs of repair or scrapping for the 20 car manufacturers; this also results in greater customer satisfaction, ie drivers of vehicles such as passenger vehicles, commercial vehicles or all-terrain vehicles equipped with particle filters. Since the charge of the particle sensor (PM sensor) used for the diagnosis, that is to say the time between two regenerations of the PM sensor, can last several minutes, the entire duration must be taken into account for evaluate the reliability of the diagnosis. This is made possible by the fact that according to a preferred variant of the method, to validate, the output signal of the field of characteristics relating to the charge of the particle filter and the volume flow rate of the exhaust gas or the gradient of the flow rate of the exhaust gas and the result of this integration is compared to a release threshold AA for the charge of the particulate filter.

6 It is expected that if this release threshold AA is exceeded, the result of the diagnosis is classified as reliable, which corresponds to case A. This first plausibility check first allows a first filtering of the result of the diagnosis as to its evaluation. In a second validation plan, for a diagnostic result classified as reliable, the result of the integration is compared with a value of a threshold B of a degree of damage to the particulate filter and in case of exceeding down from this threshold B, it is considered that the particulate filter can reliably operate (i.e., the PM emissions are below the OBD limit) and in case of overflow to the top of the this threshold B, it is considered to be certainly defective (that is, the PM emissions certainly exceed the OBD limit). In the first case, the state "particle filter tested" and "particle filter in order" are recorded. In the second case, the state "particulate filter tested" and "particle filter certainly defective" are recorded. This value of the threshold B is from the point of view of the degree of damage of the particulate filter in a gray area in which the present diagnostic result can not be exploited without further control. Therefore, when the release threshold AA is exceeded and an additional value of a threshold C is exceeded for the degree of damage of the particle filter, as upper limit of the gray area which is above the threshold value B and above an OBD limit value for an operating limit particle filter (particle filter limit model), it is diagnosed that the particle filter is certainly defective (case B). This recognition of the particle filter limit model is a central requirement of a reliable, on-board diagnostic. 30 If the release threshold AA is exceeded for a threshold C to be exceeded and a value of a threshold A of the degree of damage of the particle filter which is situated below is exceeded. of the value of the threshold B and which is taken as the lower limit of the gray range above, the diagnosis result is no longer classified as no longer usable, that is to say that

The result of the diagnosis is always in this gray range and requires further measurements. We then distinguish two other cases C and D. If the result of the diagnosis is in this gray range, that is to say that the diagnostic result is not exploitable (case D), we check if the load of the filter to particles exceeds a release threshold BB which is above the threshold value AA; in this case, active regeneration of the particulate filter is not triggered and instead the particle sensor is regenerated to restart the diagnosis of the particulate filter. In the case where the charge of the particulate filter is lower than the release threshold BB, the regeneration of the particulate filter is started and at the end, the particle sensor is regenerated as after each regeneration of the particulate filter to immediately restart the diagnosis of the particulate filter. particle filter. This means makes it possible, in the event of an uncertain, that is, non-exploitable diagnosis result, to carry out a new control of the particulate filter. In the other case (case C), that is to say in case of exceeding the release threshold AA and passing under the threshold value C and if passing under a threshold value A, records in a diagnostic unit memory unit that by its state the particle filter is operable ("particle filter in order"). This memory unit is for example an EEPROM memory. This solution has the advantage that in case of stopping the path, that is to say when stopping the engine, the result of the diagnosis will not be lost and the diagnosis can be continued after restarting the engine. It can be provided that after recording, a count function ("ghost count") is started which, for a particle filter load exceeding the threshold BB, waits for a successful regeneration and otherwise determines the duration of execution of the regeneration from a combustion regeneration model. The execution time of the particle filter diagnosis is modeled. Since this time is independent of the degree of deposition in the particulate filter, the simulated mass flow rate of the particle filter boundary model carbon black is used as the reference time. To adapt this duration to the degree of actual deposition in the particulate filter, this model is multiplied with the result stored in the diagnosis memory (the ratio between the model

8 black smoke and triggering the PM sensor). At the end of the operation of this ghost counter, the state is set to "tested" and "particle filter in order". To carry out the diagnostic process, it is planned to escalate the diagnostics with the active start of regeneration of the particulate filter only once per rolling cycle to avoid unnecessary fuel consumption or dilution of the oil. A preferred application of the process as described above is to apply it to an internal combustion engine which is a diesel engine or a gasoline engine. Particle filters are highly developed in the case of diesel engines. The future limit values imposed on the exhaust gases, in particular the maximum allowable particle load, point to an increase in the use of particulate filters also in the case of gasoline engines and the process described can then be carried out. apply advantageously in this case. The invention also relates to a device for diagnosing a particulate filter installed in the exhaust duct of an internal combustion engine according to which, it is predicted that the particle filter charge has a charge of carbon black. particle filter obtained using a particle sensor from difference measurements and / or a charge pattern of black smoke, and from the result of the diagnosis, an operation is started particle filter regeneration device, characterized in that with the diagnosis unit, the result of the particle filter diagnosis is validated with respect to its ability to operate using the relationship between the charge of the filter to the particle filter. particles and the volume flow rate of exhaust gas in the exhaust gas channel or from the gradient of the flow rate of the exhaust gases and depending on this validation, the particle filter is considered suitable to operate or as defective or the result of the diagnosis of the particulate filter is considered unworkable. According to a preferred variant, the functionality of the method with its variants can be implemented by a program

9 as an element added to a conventional diagnosis of particulate filter or OBD diagnostic or regeneration strategy in the diagnostic unit. The necessary means of application under these conditions are reduced and the equipment in the aftermarket can be done by a program update. The diagnostic unit can be an integral part of the main motor control (eg in the ECU engine management unit). Drawings The present invention will be described in more detail below with the aid of examples of a method of diagnosis of a particle filter and a device for its implementation shown in the accompanying drawings in which: FIG. 1 is a schematic view of the technical environment in which the method of the invention is inscribed; FIG. 2 is a diagram for the classification of the result of the diagnosis; FIG. 3 is a diagram showing the evolution of the degree; 4 is a diagrammatic view of different diagnostic release modes, FIG. 5 is a characteristic field of the gas / particulate charge volume flow diagram in a release range, FIG. 7 is a flowchart of a part of the function of the process. DESCRIPTION OF EMBODIMENTS OF THE INVENTION FIG. 1 is a schematic representation of the technical environment in which the invention is embodied, showing by way of example an internal combustion engine (or heat engine) 10 in the form of a diesel engine equipped with a fuel metering system 11, an air supply channel 20 receiving a supply air stream 21 and an exhaust gas channel 30 through which evacuated the mass flow of exhaust gas generated by the

In the direction of passage of the supply air duct 21, the air supply duct 20 comprises a feed air measuring device 27, for example in the form of a hot film system (HFM), a compression stage 23 forming part of a turbocharger 22 and a throttle flap 24. The exhaust gas recirculation 25 connects via a exhaust gas recycling valve 26 (abbreviated AGR valve) and a cooling radiator 28 the air supply channel 20 to the exhaust gas channel 30. In the direction of flow of the In accordance with the example shown, downstream of the internal combustion engine 10, the exhaust gas turbine 31 of the turbocharger 22 and the components of the aftertreatment system of the turbocharger 22 are exhausted. exhaust gas 40, namely a lambda probe 43, an oxidation catalyst 41 in the form of a catalyst 15 diesel oxidation catalyst (DOC catalyst), a temperature probe 44 as well as another temperature probe (not shown) and a particulate filter 42 in the form of a diesel particulate filter. In principle, other sensor arrangements may also be provided for determining the oxygen content and temperature of the exhaust gas channel upstream of the particulate filter 42. In addition, the exhaust gas channel may comprise catalysts upstream of the turbo still called PTC catalysts between the internal combustion engine 10 and the exhaust gas turbine 31, in the region of the exhaust gas manifold of the various cylinders of the internal combustion engine 25, as another component of the aftertreatment system 40. The air supply channel 20 supplies fresh air to the internal combustion engine 10. The fresh air is compressed by the compression stage 23 the turbocharger 22 driven by the volume flow of exhaust gas 46 driving the exhaust gas turbine 31. The throttle flap 24 allows to adjust the amount of air supplied. In order to reduce the pollutants, quantities of exhaust gas are mixed with the feed air stream 21 by the exhaust gas recirculation from the operating parameters of the internal combustion engine 10 from the engine. gas channel

It exhaust 30. The exhaust gas recirculation rate can be adjusted using the exhaust gas recirculation valve 26. The radiator 28 cools the exhaust gas stream from the gas channel exhaust 30.

In the exhaust aftertreatment system 40, the pollutants emitted by the internal combustion engine 10 are converted or filtered. Thus, the oxidation catalyst 41 oxidizes the hydrocarbons and the carbon monoxide. carbon while the particulate filter 42 retains the carbon black particles. The control and regulating units necessary for the operation of the internal combustion engine 10 and the exhaust after-treatment system 40 as well as, if necessary, other temperature sensors are not shown. For the diagnosis of the charge of the particulate filter 42, a diagnostic device connected to at least one particle sensor 45 (PM sensor) installed in the exhaust gas channel 30 of the engine 10 is used. The operation of the The engine 10 fills the particulate filter 42 until it reaches its storage capacity, which is then reported. Next, a regeneration phase of the particulate filter 42 is initiated in which the particles accumulated in the particulate filter 42 are burned by an exothermic reaction. To initiate this exothermic reaction, exhaust gas temperatures of the order of 600 ° C-650 ° C are required upstream of the particulate filter 42. Since these temperatures are practically only reached at full during the normal operation of the internal combustion engine 10, it is necessary to produce a rise in temperature by applying additional means. As diagrammatically shown in diagram 100 of FIG. 2, the result of the independent diagnosis of the particle filter load is guaranteed if the result of the diagnosis, starting from a 100% intact particle filter 102, is below. A zone A, 103. This zone A, 108 corresponds to a "particulate filter guaranteed in order". In the opposite case, for a degree of separation 101, too high of particulate filter up to a damaged particulate filter 107

12 to 100% or to a non-existent particulate filter 42 (empty tube) from a threshold C 106, it can be concluded independently of the charge of the particulate filter, that the particulate filter is defective 42. In this zone C 110 we have with certainty the case "particle filter defective with certainty" a particle filter limit model designed for a certain limit OBD 105, must be recognized if the result of the diagnosis is greater than a threshold B 104. Like this threshold B 104 is nevertheless in the gray zone (zone B 109), the result of the diagnosis can only be used if the charge of the particulate filter 42 (filtered charge 131, see FIG. 4) does not exceed a determined value for release AA, 133 (see Figure 4). Figure 3 shows an evolution diagram 120 giving the deterioration of the efficiency of the particulate filter 42, i.e. the deterioration of the degree of separation 122 as a function of the operating power 121 of the vehicle. The degree of separation 122 is almost 100% effective (particle filters in good order have a degree of separation, usually 95 to 97%) and it decreases very slowly at first. From a certain operating power 121 of the vehicle, the degree of separation 122 decreases sharply until finally there is no longer any filtering effect (defective filter at 100% / separation degree 122 = 0%). In zone A 108, it is considered that the result of the diagnosis is reliable, that is to say that it is correct regardless of the charge 131 of the particulate filter (see FIG. 4), that is to say that it is correct or in order. In this case, there is no triggering of the regeneration of the particulate filter by the diagnosis. From a certain operating power of the vehicle 121, for which the OBD limit value for the emission PM 123 (zone C, 110) is significantly reduced, a filter can be reliably and correctly identified. Defective particles 42 irrespective of the charge of the particulate filter 131. In this case, it is not necessary for the diagnosis to trigger a regeneration of the particulate filter. If the degree of separation 122 is in the zone B 109 (dark gray zone), the regeneration of the particulate filter will, if necessary, be actively requested, but this will be done only if the ratio between the charge 131 of the particulate filter and the volume flow rate of gas

13 exhaust (Figure 1) is above a value determined for BB 134 release (Figure 4). FIG. 4 shows another operating diagram 130 giving the charge of the particle filter 131 as a function of time from the last regeneration of the particle filter 132. The release AA 133 defines the threshold of a reliable diagnosis (range A 136) if the result of the diagnosis is in the "gray range", that is to say in the zone B 109 (see Figure 2). This release can be applied either independently of the charge of the particulate filter 131, or as a function of the charge of the particulate filter 131 and the volume flow rate of the exhaust gas 46 or the gradient of the exhaust volume flow rate 46 Since the charge of the particle sensor 45, i.e., the time between two regeneration phases of the particle sensor 45, may last several minutes, all of this time must be taken into account to assess the reliability of the diagnostic. This is made possible by the fact that a field output characteristic of the particle filter charge 131 and the exhaust gas volume flow rate 46 or the exhaust gas volume flow rate gradient 46 is integrated. If the integration value for the implementation of the particle filter diagnostic is lower than the value for the release AA 133 (zone A 136), the diagnosis is considered reliable. In the range B 137, irrespective of the diagnostic result, regeneration of the particulate filter is initiated by the onboard diagnosis. This range B 137 extends to the release BB 134 to trigger the regeneration of the particulate filter beyond diagnosis. Above this release value BB 134, there is a range C 138 in which active regeneration of the particulate filter is not initiated. This range C extends to a trip threshold 135 for normally triggered regeneration of the particulate filter. Figure 5 shows a characteristic field diagram 140 for the A133 release range A133; the volume flow rate of the exhaust gas 46 or the integration of the gradient of the volume flow rate of the exhaust gas is represented as a function of the load

14 of the particle filter 131. The trigger threshold 135 for which the regeneration of the particle filter is normally triggered has also been drawn. The functionality of the method according to the invention will be presented in FIG. 6 in the form of a flow chart 150. Based on the existence of a diagnostic result of the state of charge of the particulate filter 42 the process according to the invention (start 151). In a first interrogation 152, it is checked whether the output of the integrated characteristic field of the particle filter charge ratio 131 / exhaust volume flow rate 46 is below the AA release limit 133 If this is the case, it is considered that the result of the diagnosis is reliable, which corresponds to a case A 165. If this is not the case, it is verified by a second request 153 that the result of the diagnosis is above the threshold C 106 (see Figure 2). If this is not the case, we go to case B 166 (the particle filter is certainly defective and as a result 161, we "test" a condition and we consider it "defective"). The diagnosis is thus completed. If the result of the second interrogation 153 gives a negative response, then by a third interrogation 154, it is checked whether the result of the diagnosis is below the threshold A 103 (see FIG. 2). If this is the case, it is in the case C 167, that is to say that the particle filter 42 will be classified as certainly in order. If this is not the case, it is in the case D 168, that is to say that the functionality of the particle filter 42 is in the gray zone (see the zone B 109 of FIG. 2). If the charge of the particulate filter 131 exceeds the release threshold BB 134 (see FIG. 4), active regeneration of the particulate filter can not be triggered. In a functional block 158, the particle sensor 45 is regenerated to restart the diagnosis of the particulate filter. If the charge of the particulate filter 131 is lower than the release threshold BB 134 (see FIG. 4), an active regeneration of the particulate filter is deactivated in the functional block 156. By another interrogation 157, it is checked whether the regeneration Particle filter is complete. If not, regeneration is continued. If the regeneration is complete, regenerate the

15 particle sensor 45 in the function block 158 to restart the diagnosis of the particulate filter. In the case A 165, a query 159 checks whether the result of the diagnosis is below the threshold B 104 (see FIG. 2). If this is the case, we put the result 160 on the state "tested" and "in order". The diagnosis is thus completed. But if the result of the diagnosis exceeds the threshold B 104, we put the result 161 as in the case B 166, the state on "tested" and "defective", which ends the diagnosis. In case C 167, the result lo of the diagnosis is first recorded in a memory (for example an EEPROM memory) in a function block 162 so as not to lose the result in case of stopping the path. This allows the diagnosis to continue at the next engine restart. In the next function block 163, a ghost counter is started. This partial function is shown separately in FIG. 7. By interrogation 164, it is checked whether the phantom counter has finished counting. If this is the case, the result is 160, the state "tested" and "in order" as in case A 165. The diagnosis is thus completed. In the case of a demonstration of the onboard diagnosis, case A 165 is used because the boundary model particle filter is re-generated directly before the OBD demonstration test before pre-conditioning. Once regeneration of the particulate filter is successful, the PM sensor must also be regenerated so that the diagnosis of the particulate filter can be made after regeneration of the sensor. FIG. 7 shows as another functional flow 150 the "ghost counter" partial function consisting in the function block 163 to start the "ghost counter" and check with a subsequent interrogation 169 whether the charge of the particulate filter 131 exceeds the threshold If this is the case, a successful regeneration is awaited (functional block 173). In the opposite case, the duration of execution of a particle filter regeneration is modeled from a combustion model in the functional block 170. Then, the duration of the diagnosis procedure of the particle filter (charge particle sensor 45). Since this duration depends on the deposition degree in the particulate filter 122, the mass flow of black from

Smoke, simulated, from the reference model is used as the reference duration. To adapt this duration to the actual degree of deposition, this model is multiplied by the result recorded in the diagnosis memory, that is to say the ratio between the lamp black model and the triggering of the PM sensor (functional block 171). The ghost counter has finished counting and the diagnosis can continue. Since it may happen that the phantom meter has not finished counting until the next diagnostic result is available, several diagnostic results are recorded and several phantom counters can be calculated in parallel. It can then be provided that the operation of the ghost counter and the parallel calculations take place over several rolling cycles. 15

17 NOMENCLATURE

10 Internal combustion engine 11 Fuel metering system 20 Air supply duct 21 Supply air duct 23 Turbocharger 24 Throttle flap 25 Exhaust gas recirculation 26 Exhaust gas recirculation valve 27 Supply air metering system 28 Radiator 30 Exhaust gas duct 31 Exhaust gas turbine 40 Exhaust aftertreatment system 41 Oxidation catalyst 42 Particulate filter 43 Lambda probe 44 Probe of temperature 46 Exhaust volume flow rate 102 Intact particulate filter 103 Threshold A 104 Threshold B 105 OBD limit 107 Particle filter 100% damaged 108 Zone A Particle filter certainly in order 109 Zone B / gray zone 110 Zone C particle filter definitely defective 120 Diagram of the deterioration of the capacity of the particle filter 121 Driving power 122 Degree of separation as a function of the driving power 123 Limit value OBD emission PM 130 Particle filter charge diagram 131 Particulate filter charge

18 132 Time counted from the last regeneration of the particulate filter 133 Release AA 134 Release BB 135 Start point for regeneration of the particulate filter under normal conditions 136 Range A 137 Range B 140 Characteristic field diagram 150 Flow chart Process of the Invention 151-173 Steps of the Process 15015

Claims (1)

CLAIMS 1 °) A method of diagnosis of a particulate filter (42) installed in the exhaust gas channel (30) of an internal combustion engine (10) in which it is predicted that the charge of carbon black from the filter to particles (42) the charge of the particulate filter (131) obtained using a particle sensor (45) from difference measurements and / or a charge pattern of carbon black, and from of the diagnostic result, a regeneration operation of the particulate filter (42) is started, characterized in that the result of the diagnosis of the particulate filter (42) is validated as to its ability to function, from a relationship between the particulate filter charge (131) and a volume flow rate of exhaust gas (46) in the exhaust gas channel (30) or a volume flow gradient of the exhaust gas (46) and according to this validation, the particle filter (42) is classified as capable of functioning or faulty or the result of the diagnosis of the particulate filter (42) is considered unusable. Method according to Claim 1, characterized in that for the validation, the output of the characteristic field for the charge of the particulate filter (131) and the volume flow rate of the exhaust gas (46) or the gradient of the exhaust gas volume flow rate (46) and the result of this integration is compared to a threshold for AA release (133) of the charge of the particulate filter (131). 3) Method according to one of claims 1 or 2, characterized in that if the threshold for the release AA (133) is exceeded, the result of the diagnosis is classified as reliable. 4) Method according to claim 1, characterized in that for a diagnostic result classified as reliable, the result of the integration is compared with the value of a threshold B (104) of the degree of harmfulness of the particulate filter. (101), * when passing below threshold B (104), the particulate filter (42) is classified as reliably operable and in the event of a break-up of threshold B (104), it is classified as definitely defective. Method according to claim 1 or 2, characterized in that it is diagnosed that the particulate filter (42) is certainly defective in case of exceeding the threshold for the AA release (133) and in case of exceeding in addition to a threshold value C (106) for the degree of harmfulness of the particulate filter (101) which is above the threshold value B (104) and above an OBD limit value for PM emissions (105) for a particle filter (42) whose operation is at the limit. 6. Process according to claim 1, characterized in that the result of the diagnosis is classified as not being exploitable if the threshold for the release AA is exceeded (133), not-wise under the value of threshold C (106) and exceeding a threshold value A (103) for the degree of harmfulness of the particulate filter (101) which is below the threshold value B (104). Method according to Claim 6, characterized in that, in the case of a non-usable diagnostic result, it is checked whether the charge of the particulate filter (131) exceeds the release threshold BB (134) which is above of the threshold value AA (133), and in this case, active regeneration of the particulate filter (42) is not triggered and instead the particle filter (45) is regenerated and in case the charge of the particulate filter (131) is below the release threshold BB (134), 21 a regeneration of the particulate filter (42) is initiated and after this regeneration, the particulate filter (45) is regenerated. Method according to Claim 1, characterized in that when the release threshold AA (133) is exceeded and the threshold value C (106) is exceeded, and if passing a threshold value A (103) downwards, the state of the operable particle filter (42) is recorded in a memory unit. Method according to Claim 8, characterized in that after recording in memory a counting function is started, for which, if the charge of the particulate filter (131) exceeds the threshold BB (134), then expects the regeneration to be successful and otherwise the regeneration run time is determined from a combustion model. Process according to Claim 1, characterized in that the diagnostics are carried out by the active start of regeneration of the particulate filter only once per cycle of con duct. 11 °) Application of the method according to one of claims 1 to 10 to an internal combustion engine (10) equipped with a diesel engine or a gasoline engine. 12) A device for diagnosing a particulate filter (42) installed in the exhaust gas duct (30) of an internal combustion engine (10) according to which the charge of carbon black of the filter is predicted. particulate filter (42) the charge of the particle filter (131) obtained using a particle sensor (45) from difference measurements and / or a charge pattern of lampblack, and from the result 22 of the diagnosis, a regeneration operation of the particle filter (42) is started, characterized in that with the diagnostic unit the diagnosis result of the particulate filter (42) is validated. its ability to function by the relationship between the particulate filter charge (131) and the exhaust gas volume flow rate (46) in the exhaust gas channel (30) or at least one of of the gradient of the volume flow of the exhaust gases (46) and according to this validation, the filt is considered re particulate (42) lo as operable or as defective or the result of the diagnosis of the particulate filter (42) is considered as not exploitable, the diagnostic unit comprising means for carrying out the process according to l any of claims 1 to 10.