KR102583976B1 - Method and device for diagnosing a coated otto particle filter of an exhaust tract of an internal combustion engine - Google Patents

Abstract

The present invention relates to a method and device for diagnosing a coated gasoline particulate filter 140 of an exhaust gas pipe 100 of an internal combustion engine, wherein the exhaust gas pipe 100 is a coated gasoline particulate filter 140, an exhaust gas A first NOx-/NH3- sensor 130 arranged upstream of the gasoline particulate filter 140 in the flow direction, and a second NOx-/NH3-sensor 130 arranged downstream of the gasoline particulate filter 140 in the exhaust gas flow direction. Equipped with an NH3-sensor 150, in this case the method according to the invention comprises the following steps:
- A step of operating the internal combustion engine, wherein the exhaust gas flows through the exhaust gas pipe 100;
- detecting a first measurement signal 342 using a first NOx-/NH3-sensor (130) characterizing the NH3-concentration in the exhaust gas upstream of the gasoline particulate filter (140);
- detecting a second measurement signal (352) downstream of the gasoline particulate filter (140) using a second NOx-/NH3-sensor (150) characterizing the NH3-concentration in the exhaust gas; and
- evaluating the first measurement signal 342 and the second measurement signal 352 to diagnose the coated gasoline particulate filter 140.

Description

Method and device for diagnosing a coated gasoline particulate filter of an exhaust gas pipe of an internal combustion engine {METHOD AND DEVICE FOR DIAGNOSING A COATED OTTO PARTICLE FILTER OF AN EXHAUST TRACT OF AN INTERNAL COMBUSTION ENGINE}

The present disclosure relates to a method and apparatus for diagnosing a coated gasoline particulate filter of an exhaust gas pipe of an internal combustion engine, wherein the exhaust gas pipe of the coated gasoline particulate filter is a coated gasoline particulate filter, said coating in the exhaust gas flow direction. a first NOx-/NH3-sensor arranged upstream of the coated gasoline particulate filter, and a second NOx-/NH3-sensor arranged downstream of the coated gasoline particulate filter in the exhaust gas flow direction.

The exhaust gas pipe of an internal combustion engine is designed to after-process the exhaust gases originating from the combustion chamber and to guide the exhaust gases to the surrounding environment. In the case of exhaust gas aftertreatment, for example, pollutants are filtered or reduced from the exhaust gases. Due to increasingly stringent regulations from different authorities, more and more gasoline engines are equipped with particulate filters, with the result that particulates originating from exhaust gases are bound within the particulate filter, preventing the particulates from entering the surrounding environment. Gasoline particulate filters filter a significant portion of the particulates produced during combustion from exhaust gases. Additionally, the exhaust pipe may be equipped with an exhaust catalytic converter that reduces pollutants such as hydrocarbons, carbon monoxide and nitrogen oxides to harmless exhaust gas components such as water and carbon dioxide.

The function of the gasoline particulate filter is typically realized by evaluating the differential pressure signal through the gasoline particulate filter. However, these conventional methods for monitoring the function of gasoline particulate filters are inaccurate and cannot reliably detect potential damage or defects within the gasoline particulate filter. Due to the unreliable diagnosis of gasoline particulate filters for damage, authorities worldwide have not yet defined strict particulate count thresholds, as no robust solution for detecting damaged gasoline particulate filters has hitherto been available. .

Therefore, the object of the present disclosure is to provide a method and device that can perform reliable diagnosis of a gasoline particulate filter of an exhaust gas pipe of an internal combustion engine.

The above problem is solved by the features of the independent patent claims. Preferred embodiments of the disclosure are specified in the dependent claims.

According to the present disclosure, a method for diagnosing a coated gasoline particulate filter of an exhaust gas pipe of an internal combustion engine includes a coated gasoline particulate filter, a first NOx-/ an NH3-sensor and a second NOx-/NH3-sensor arranged downstream of the coated gasoline particulate filter in the exhaust gas flow direction. The NOx-/NH3-sensor may include a NOx-sensor or a NH3-sensor (ammonia sensor). Accordingly, the exhaust gases originating from the internal combustion engine and flowing through the exhaust pipe first pass through the first NOx-/NH3-sensor and then into the coated gasoline particulate filter and then into the second NOx-/NH3-sensor. -Pass through the sensor. Coated gasoline particulate filters are designed to filter out particulates from exhaust gases. According to the present disclosure, in the first method step, the internal combustion engine is operated, thereby causing exhaust gases to flow through the exhaust pipe, because the air-fuel mixture is combusted within the combustion chamber of the internal combustion engine, thereby causing the exhaust gas pipe to flow. This is because exhaust gas is generated that passes through and is released into the surrounding environment. Within this exhaust gas, there may be particulates that must be filtered out by a coated gasoline particulate filter.

According to the present disclosure, in a second step, a first measurement signal characterizing the NH3- concentration in the exhaust gas is detected upstream of the gasoline particulate filter using a first NOx-/NH3-sensor. Accordingly, in the first measurement signal the NH3- concentration in the exhaust gas can be detected upstream of the coated gasoline particulate filter. The NOx-sensor detected the measurement signal with NH3 cross-sensitivity, from which the NH3-concentration could be determined. According to the present disclosure, in another step, downstream of the gasoline particulate filter, a second measurement signal characterizing the NH3- concentration in the exhaust gas is detected using a second NOx-/NH3-sensor. Accordingly, using the second measurement signal, the NH3- concentration in the exhaust gas can be detected downstream of the coated gasoline particulate filter. According to the present disclosure, in another step, the first measurement signal and the second measurement signal are evaluated to diagnose a coated gasoline particulate filter. A coated gasoline particulate filter according to the present disclosure converts gaseous pollutants, especially hydrocarbons, carbon monoxide and nitrogen oxides, from exhaust gases in parallel with the filtration of particulates. In order to carry out the conversion even in slightly oxygen-rich or slightly oxygen-deficient conditions, the coating of the gasoline particulate filter typically has oxygen storage properties, according to one embodiment.

If within the first measurement signal of the first NOx-/NH3-sensor an increase in the NH3-concentration in the exhaust gas can be seen, for example upstream of the coated gasoline particulate filter, then more NH3 will be present in the coated gasoline particulate filter. flows into me. The conversion capability of the coated gasoline particulate filter allows NH3 entering the gasoline particulate filter to be converted and thereby reduced. Accordingly, if the gasoline particulate filter is not damaged, the NH3-concentration varies across the coated gasoline particulate filter. Accordingly, using the second measurement signal, differences in NH3-concentration due to the conversion properties of the coated gasoline particulate filter can be detected. The first measurement signal and the second measurement signal can be used to diagnose a gasoline particulate filter coated according to the present disclosure, such that a conclusion can be drawn as to whether conversion of NH3 has occurred in the gasoline particulate filter. . If the gasoline particulate filter is damaged, a portion of the NH3 will flow through the gasoline particulate filter unhindered, and this can be seen in the second measurement signal. Accordingly, according to the present disclosure, the diagnosis of a gasoline particulate filter can be carried out in a very simple and accurate manner and manner. This can lead to the detection of damage, for example cracks due to high thermal stresses in the coated gasoline particulate filter.

According to one embodiment, for the evaluation a first measurement signal is compared with a second measurement signal and if an increase in NH3-concentration is detected almost simultaneously in the first measurement signal and in the second measurement signal, the coated gasoline particulates The filter is recognized as damaged. If the coated gasoline particulate filter is damaged, NH3 can flow through the coated gasoline particulate filter almost unhindered, which will cause the NH3-concentration detected within the measurement signal of the first NOx-/NH3-sensor to change. The increase follows almost simultaneously the increase in the NH3-concentration detected in the second measurement signal of the second NOx-/NH3-sensor. Accordingly, in this way, the diagnosis of the gasoline particulate filter related to damage to the gasoline particulate filter can be preferably recognized simply but also accurately. Comparison of the second measurement signal with the first measurement signal may include calculation of efficiency, difference, or filtering, depending on one embodiment.

According to one embodiment, the coated gasoline particulate filter can store oxygen that is used for the conversion of NH3, where the method is only carried out if a predetermined amount of oxygen is present in the coated gasoline particulate filter. NH3 can be converted by oxygen in the coated gasoline particulate filter. If no oxygen is present in the coated gasoline particulate filter for conversion, then also no or little NH3 is converted, with the result that NH3 passes through the coated gasoline particulate filter in an unconverted/unhindered state. It flows. Accordingly, if this method is performed when no oxygen is present in the gasoline particulate filter, NH3 will flow through the gasoline particulate filter unimpeded or unconverted, thereby diagnosing damage to the gasoline particulate filter. It can be. Situations like this must be avoided. Accordingly, this method should only be carried out if a predetermined amount of oxygen (e.g. 50% of the maximum possible oxygen concentration) is present in the coated gasoline particulate filter, for the reasons already explained in this case only. This is because NH3 is converted within the coated gasoline particulate filter as described. NH3 is converted by oxygen in the coated gasoline particulate filter, thereby distinguishing the measurement signal of the first NOx-/NH3-sensor from the measurement signal of the second NOx-/NH3-sensor. This distinction can be interpreted to mean that the gasoline particulate filter is not damaged. If, despite the presence of sufficient oxygen, the increase in the measurement signal of the NOx-/NH3-sensor directly follows the increase in the second measurement signal of the second NOx-/NH3-sensor, then there is a corresponding damage to the gasoline particulate filter. Alternatively, a conclusion may be drawn about reduced efficiency. According to this embodiment, the accuracy of this method can be further advantageously increased.

According to one embodiment, the exhaust gas pipe of the internal combustion engine is provided with an exhaust gas catalytic converter arranged upstream of the first NOx-/NH3-sensor, so that the exhaust gases first flow through the exhaust gas catalytic converter, In this case, the operation of the internal combustion engine is performed substoichiometrically, and as a result, the exhaust gas catalytic converter produces NH3, and the detection and evaluation of the first and second measurement signals for diagnosing the gasoline particulate filter are NH3. It only starts when the exhaust gas escapes from the catalytic converter. Exhaust catalytic converters are designed to combine and reduce pollutants from exhaust gases. When the internal combustion engine operates substoichiometrically, fuel residues (HC hydrocarbons) that could not be burned due to lack of oxygen remain in the exhaust gases. These residues reach the exhaust catalytic converter, where they are converted together with pollutants. While these pollutants and hydrocarbons are converted within the exhaust gas catalytic converter, NH3 is produced, and NH3 can then react with oxygen stored within the exhaust gas catalytic converter to form nitrogen and water. . When stored oxygen is supplied and NH3 continues to be produced due to conversion of pollutants within the exhaust gas catalytic converter, NH3 flows out of the exhaust gas catalytic converter. NH3 leaking out from the exhaust gas catalytic converter can be detected by the first NOx-/NH3-sensor, whereby the first measurement signal and the second measurement signal for diagnosing the gasoline particulate filter according to this embodiment are used. Detection and evaluation begin. According to this embodiment, the stoichiometric operation of the internal combustion engine produces NH3 as intended within the exhaust catalytic converter, thereby allowing the method for diagnosing coated gasoline particulate filters to perform as intended. there is. Accordingly, the method can be implemented at predefined operating points of the internal combustion engine, whereby the diagnosis of the coated gasoline particulate filter can additionally be carried out advantageously accurately.

According to one embodiment, the emission of NH3 from the exhaust catalytic converter is monitored using a first NOx-/NH3-sensor and detection of the first and second measurement signals for diagnosing the coated gasoline particulate filter. And the evaluation begins only when an increase in NH3- concentration is detected in the first measurement signal of the first NOx-/NH3- sensor. According to the present embodiment, NH3 slip or NH3 penetration through the exhaust gas catalytic converter can be detected in a reliable type and manner, and such NH3 slip or NH3 penetration can trigger the detection and evaluation of the measurement signal. . According to the present embodiment, this method can be implemented as intended if the necessary increase in NH3- concentration in the exhaust gases is present downstream of the exhaust gas catalytic converter.

According to one embodiment, the exhaust gas pipe of the internal combustion engine is provided with a lambda sensor arranged upstream of the exhaust catalytic converter and designed to detect the oxygen concentration in the exhaust gas, thereby reducing the substoichiometric level of the internal combustion engine. The operation can be detected/monitored, whereby detection and evaluation of the first and second measurement signals can be prepared for diagnosing the coated gasoline particulate filter. Accordingly, by reference to the signal of the lambda sensor upstream of the exhaust gas catalytic converter, it can be detected whether the internal combustion engine is operated stoichiometrically, sub-stoichiometrically or super-stoichiometrically. If, by reference to the signal from the lambda sensor, the internal combustion engine is recognized as operating substoichiometrically for a predetermined period, it can be concluded that NH3 is produced in the exhaust catalytic converter, and oxygen is produced in the exhaust catalytic converter. As consumed, NH3 exits the exhaust catalytic converter and enters the coated gasoline particulate filter. Therefore, according to the present embodiment, a method can be prepared for diagnosing a coated gasoline particulate filter, if the signal of the lambda sensor allows this.

According to one embodiment, the first NOx-/NH3-sensor and/or the second NOx-/NH3-sensor are NOx-sensors.

By reference to the signal of the NOx-sensor, conclusions can be drawn about the concentration of NH3 and, consequently, NH3-concentration upstream and/or downstream of the coated gasoline particulate filter, depending on the situation, by means of a pre-installed NOx-sensor. can be detected or determined. The NOx sensor upstream or downstream of the coated gasoline particulate filter can already be installed in the conventional exhaust pipe, especially in the case of diesel, and consequently, according to the present embodiment, the method can be used without any additional components. It can be implemented in the exhaust gas pipe of

According to one embodiment, the first NOx-/NH3-sensor and/or the second NOx-/NH3-sensor are NH3-sensors. The NH3-sensor is designed only to detect the NH3-concentration at its own location, i.e. upstream or downstream of the coated gasoline particulate filter. The NH3-sensor thus supplies the concentration of NH3/ammonia directly and preferably of the correct type and manner in its arrangement position, in this case upstream or downstream of the coated particulate filter.

According to another aspect of the present disclosure, an apparatus for diagnosing a coated gasoline particulate filter of an exhaust gas pipe of an internal combustion engine is proposed, wherein the exhaust pipe has a coated gasoline particulate filter downstream of the gasoline particulate filter in the flow direction. a first NOx-/NH3-sensor arranged in and a second NOx-/NH3-sensor arranged downstream of the coated gasoline particulate filter in the flow direction, with a control unit designed to control one of the methods described above. . The device may for example be a control unit for controlling/regulating an internal combustion engine. It is also conceivable that this device is part of a control unit or is installed as an additional control unit, for example in a vehicle with an internal combustion engine.

Embodiments and improvements of the method and apparatus according to the present disclosure are shown in the respective drawings and are described in more detail with reference to the detailed description below.
In the drawing department:
1 shows a schematic diagram of an exhaust gas pipe of an internal combustion engine according to one embodiment, and
2 shows a first diagram with a plurality of sub-diagrams according to one embodiment.

Figure 1 shows the exhaust gas pipe 100 of an internal combustion engine, in this case the exhaust gas pipe 100 includes a lambda sensor 110, an exhaust gas catalytic converter 120, a first NOx-/NH3-sensor 130, and a coating. Equipped with a gasoline particulate filter (140) and a second NOx-/NH3-sensor (150). The exhaust gas catalytic converter 120 is arranged downstream of the lambda sensor 110 in the direction of exhaust gas flow. The first NOx-/NH3-sensor 130 is arranged downstream of the exhaust gas catalytic converter 120 in the exhaust gas flow direction. The coated gasoline particulate filter 140 is arranged downstream of the first NOx-/NH3-sensor 130 in the exhaust gas flow direction. The second NOx-/NH3-sensor 150 is arranged downstream of the gasoline particulate filter 140 in the exhaust gas flow direction. The lambda sensor 110 is designed to detect the oxygen content of the exhaust gas upstream of the exhaust gas catalytic converter 120. The exhaust catalytic converter 120 is designed to convert and reduce pollutants, particularly hydrocarbons, carbon monoxide and nitrogen oxides, from exhaust gases. The first NOx-/NH3-sensor 130 is designed to detect a measurement signal characterizing the NH3-concentration downstream of the exhaust catalytic converter 120 and upstream of the coated gasoline particulate filter 140. The coated gasoline particulate filter 140 is designed to filter particulates from the exhaust gases and further convert and reduce pollutants, especially hydrocarbons, carbon monoxide and nitrogen oxides, from the exhaust gases using the coating. The second NOx-/NH3-sensor 150 is designed to detect a measurement signal characterizing the NH3-concentration of the exhaust gas downstream of the coated gasoline particulate filter 140. In Figure 1, the lambda sensor 110, the first NOx-/NH3-sensor 130, the second NOx-/NH3-sensor 150 and, in some cases, are designed to process measurement signals from another sensor. A control unit 200 is additionally shown. In addition, the control unit 200 is configured to perform a method or diagnosis of the coated gasoline particulate filter 140 and, if necessary, to perform fault registration in the fault memory and further, if necessary, to perform a diagnostic test on the coated gasoline particulate filter 140 and the damaged gasoline particulate filter 140 . It is designed to output related errors to the user of the internal combustion engine.

Figure 2 shows a diagram 300 with a plurality of subdiagrams 310-350, each depicting a different variable over time. The first sub-diagram 310 shows the lambda value 312 of the lambda sensor 110 over time. The second sub-diagram 320 shows the oxygen content or oxygen mass 322 within the exhaust catalytic converter 120 over time. The third sub-diagram 330 shows the oxygen content or oxygen mass 332 in the gasoline particulate filter 140 over time. The fourth sub-diagram 340 shows the first measurement signal 342 and thus the NH3-concentration upstream of the gasoline particulate filter 140 over time. The fifth sub-diagram 350 shows the second measurement signal 352 and thus the NH3-concentration downstream of the gasoline particulate filter 140 over time.

In the first sub-diagram 310, the internal combustion engine is first operated super-stoichiometrically, then sub-stoichiometrically, then super-stoichiometrically again, and then stoichiometrically. You can see that this situation can be known by referring to the lambda value (312). Stoichiometric operation is indicated by dashed line 314 in the first sub-diagram 310. Stoichiometric operation is ensured when lambda = 1, i.e. when sufficient fuel and oxygen fractions are present for complete combustion of the mixture.

In the second sub-diagram 320, it is shown that despite super-stoichiometric operation, the oxygen content or oxygen mass 322 within the exhaust catalytic converter 120 no longer increases, i.e. within the catalytic converter 120. You can see that the maximum oxygen load has already been reached. As soon as the internal combustion engine operates substoichiometrically, oxygen in the exhaust catalytic converter 120 is reduced due to reduction of NH3 to nitrogen and water and no additional oxygen is introduced into the exhaust catalytic converter 120 by the exhaust gases. Mass 322 descends. Then in the second sub-diagram 320 it can be seen that as soon as there is no more oxygen in the exhaust catalytic converter 120, the oxygen content or oxygen mass 322 has reached a minimum value. As soon as the internal combustion engine is again operated super-stoichiometrically, i.e. as soon as additional oxygen is present in the exhaust gases and thus supplied to the exhaust gas catalytic converter 120, the oxygen content or oxygen mass in the exhaust gas catalytic converter 120 (322) increases again because oxygen is stored again. As soon as the internal combustion engine is operating stoichiometrically again, the oxygen content or oxygen mass 322 remains constant. In other words, no more new oxygen is stored because there is no oxygen to be provided in the exhaust gases, but since NH3 does not need to be reduced, no oxygen is needed for the reduction of NH3.

In the third sub-diagram 330, the oxygen content or oxygen mass 332 in a coated Gasoline Particulate Filter (GPF) 140 is shown over time. In this sub-diagram, the oxygen content or oxygen mass 332 is initially constant at a high level from the point when there is no more oxygen in the exhaust catalytic converter until the oxygen content or oxygen mass 332 decreases as well. It can be seen that it is maintained. This situation occurs when NH3 is delivered into the exhaust gas by the exhaust gas catalytic converter 120 and thereby reaches the coated gasoline particulate filter 140. The NH3 is reduced within the coated gasoline particulate filter 140 as long as oxygen is present within the coated gasoline particulate filter 140. From the point where oxygen is no longer present within the gasoline particulate filter 140, no further reduction of NH3 occurs and the oxygen content or oxygen mass 332 reaches its minimum value within the gasoline particulate filter 140. I do it.

The fourth sub-diagram 340 shows the first measurement signal 342 and thus the NH3-concentration downstream of the exhaust catalytic converter 120 and upstream of the coated gasoline particulate filter 140. From the fourth sub-diagram 340, it can be seen that the NH3-concentration downstream of the exhaust catalytic converter 120 is zero or You can see that it does not exist at all. As soon as there is no longer oxygen in the exhaust catalytic converter 120 , NH3 penetration occurs, which results in an increase in NH3- concentration downstream of the exhaust catalytic converter 120. This situation can be seen from the first measurement signal 342 in the fourth sub-diagram 340. As soon as oxygen is supplied to the exhaust gas catalytic converter 120 again, the concentration of NH3 downstream of the exhaust gas catalytic converter 120 begins to drop again, which may cause NH3 to decrease again.

The fifth sub-diagram 350 shows two second measurement signals 352 over time, whereby these measurement signals represent NH3 downstream of the gasoline particulate filter 140 at different states of the gasoline particulate filter 140. -Draw the concentration. The second measurement signal 352a shown in the fifth sub-diagram 350 shows a damaged coated gasoline particulate filter 140. The second measurement signal 352b shown in the fifth sub-diagram 350 shows the measurement signal from a gasoline particulate filter 140 that is intact and capable of functioning. The NH3-concentration downstream of the gasoline particulate filter 140 in a damaged gasoline particulate filter 140 follows the NH3-concentration upstream of the gasoline particulate filter 140 almost simultaneously. Accordingly, it can be seen here that NH3 flows through the gasoline particulate filter 140 in an unconverted state. Accordingly, the gasoline particulate filter 140 may, for example, have cracks, with the result that NH3 can flow through unhindered. Accordingly, damage to the gasoline particulate filter 140 can be confirmed with reference to the first measurement signal 342 and the second measurement signal 352. The intact gasoline particulate filter 140 in the presence of oxygen converts NH3, with the result that initially no NH3 is discharged from the gasoline particulate filter 140. As soon as oxygen is no longer present in the gasoline particulate filter 140, NH3 is released from the intact gasoline particulate filter 140, resulting in a higher NH3-concentration downstream of the gasoline particulate filter 140. also increases. However, this increase occurs in a time offset state. This time offset can be seen in the fifth subdiagram 350 using the second measurement signal 352b shown, which increases only as soon as there is no more oxygen in the gasoline particulate filter 140 to convert NH3. is shown {see third subdiagram 330}. Accordingly, if the increase in the second measurement signal 352b is offset in time with respect to the increase in the first measurement signal 342, it can be concluded that the coated gasoline particulate filter 140 is capable of functioning. It can be taken down.

Claims (9)

As a method for diagnosing the gasoline particulate filter 140 of the exhaust gas pipe 100 of an internal combustion engine,
The exhaust gas pipe 100 includes a coated gasoline particulate filter 140, a first sensor 130 arranged upstream of the gasoline particulate filter 140 in the exhaust gas flow direction, and a gasoline particulate filter ( It has a second sensor 150 arranged downstream of 140, and the method includes:
- A step of operating the internal combustion engine, wherein the exhaust gas flows through the exhaust gas pipe 100;
- detecting a first measurement signal 342 using a first sensor 130 characterizing the NH3-concentration in the exhaust gas upstream of the gasoline particulate filter 140;
- detecting a second measurement signal 352 using a second sensor 150 characterizing the NH3-concentration in the exhaust gas downstream of the gasoline particulate filter 140; and
- evaluating the first measurement signal 342 and the second measurement signal 352 to diagnose the coated gasoline particulate filter 140
Including,
The coated gasoline particulate filter 140 can store oxygen that is used for conversion of NH3, wherein the method is carried out only when a predetermined amount of oxygen is present in the coated gasoline particulate filter 140. Method for diagnosing gasoline particulate filters in engine exhaust pipes. 2. The method of claim 1, wherein for evaluation the first measurement signal (342) is compared with the second measurement signal (352), NH3 within the first measurement signal (342) and within the second measurement signal (352). - A method for diagnosing a gasoline particulate filter of an exhaust gas pipe of an internal combustion engine, recognizing that the coated gasoline particulate filter 140 is damaged when an increase in concentration is simultaneously detected. delete 3. The method according to claim 1 or 2, wherein the exhaust gas pipe (100) of the internal combustion engine is provided with an exhaust gas catalytic converter (120) arranged upstream of the first sensor (130), so that the exhaust gas is first The exhaust gas flows through the catalytic converter 120, and in this case, the operation of the internal combustion engine is performed substoichiometrically, and as a result, the exhaust gas catalytic converter 120 produces NH3, and the gasoline particulate filter 140 The detection and evaluation of the first measurement signal 342 and the second measurement signal 352 for diagnosing the gasoline particulates in the exhaust gas pipe of the internal combustion engine begins only when NH3 flows out from the exhaust gas catalytic converter 120. How to diagnose a filter. 5. The method of claim 4, wherein the outflow of NH3 from the exhaust gas catalytic converter (120) is monitored using a first sensor (130) and a first measurement signal (342) for diagnosing the coated gasoline particulate filter (140). ) and the detection and evaluation of the second measurement signal 352 is started only when an increase in NH3- concentration is detected within the first measurement signal 342 of the first sensor 130. Methods for diagnosing particulate filters. 5. The method of claim 4, wherein the exhaust gas pipe (100) of the internal combustion engine is provided with a lambda sensor (110) arranged upstream of the exhaust gas catalytic converter (120) and designed to detect the oxygen concentration in the exhaust gas, This allows the substoichiometric operation of the internal combustion engine to be detected, whereby detection and evaluation of the first measurement signal 342 and the second measurement signal 352 diagnose the coated gasoline particulate filter 140. A method for diagnosing a gasoline particulate filter of an exhaust gas pipe of an internal combustion engine, which can be prepared to do so. 3. Method according to claim 1 or 2, wherein the first sensor (130) or the second sensor (150) is a NOx sensor. 3. Method according to claim 1 or 2, wherein the first sensor (130) or the second sensor (150) is an NH3 sensor. A device for diagnosing the gasoline particulate filter (140) of the exhaust gas pipe (100) of an internal combustion engine, comprising:
The exhaust gas pipe 100 includes a coated gasoline particulate filter 140, a first sensor 130 arranged upstream of the gasoline particulate filter 140 in the exhaust gas flow direction, and a coated gasoline particulate filter in the exhaust gas flow direction. Gasoline particulate filter (140) of the exhaust gas pipe of an internal combustion engine, comprising a second sensor (150) arranged downstream of (140) and a control unit (200) designed to control the method according to claim 1 or 2. A device for diagnosing.