DPF carbon load determination method, device and vehicle

Abstract

The present invention belongs to the technical field of vehicles and discloses a DPF carbon load determination method, device and vehicle. The DPF carbon load determination method includes: querying a pressure difference carbon load model according to the DPF flow resistance at the current moment to determine the basic carbon load at the current moment; querying a first preset MAP according to the current vehicle speed and the current vehicle acceleration to determine the first carbon load correction factor at the current moment; querying a second preset MAP according to the current DPF temperature and the current DPF upstream nitrogen dioxide flow to determine the second carbon load correction factor at the current moment; determining the first carbon load correction coefficient at the current moment according to the first carbon load correction factor at the current moment and the second carbon load correction factor at the current moment; and correcting the basic carbon load at the current moment according to the first carbon load correction coefficient at the current moment to obtain the first corrected carbon load at the current moment.

Description

Technical Field

[0001] The present invention relates to the field of vehicle technology, and in particular to a method and device for determining DPF carbon load, and a vehicle. Background Art

[0002] Engine exhaust not only pollutes the environment but also harms human health. To mitigate these hazards, a DPF (Diesel Particulate Filter) is often used to filter particulate matter from engine exhaust. Over time, the DPF trap accumulates particulate matter, which can increase engine backpressure and reduce engine performance. Therefore, it is necessary to remove particulate matter deposited within the DPF—in other words, to clear the carbon load within the DPF—to restore its filtering performance. The key to clearing the carbon load within the DPF is to let the controller know when the carbon load has reached its upper limit.

[0003] In existing technology, a differential pressure sensor is typically used to measure the pressure differential across the DPF. The DPF flow resistance is calculated based on the pressure differential and the exhaust gas flow rate passing through the DPF. The DPF carbon load is then determined based on the relationship between the DPF flow resistance and carbon load, known as the differential pressure carbon load model. However, due to the structural characteristics of the DPF, during passive DPF regeneration, the pressure differential decreases much faster than the carbon load decreases. This results in inaccurate carbon load estimates from the differential pressure carbon load model, which can easily lead to frequent DPF regeneration or even burnout.

[0004] Therefore, there is an urgent need for a method, device and vehicle for determining the carbon load of a DPF to solve the above problems. Summary of the Invention

[0005] The object of the present invention is to provide a method, device and vehicle for determining the carbon load of a DPF, so as to accurately determine the carbon load of the DPF.

[0006] To achieve this object, the present invention adopts the following technical solutions:

[0007] The method for determining DPF carbon load includes:

[0008] Query the pressure difference carbon load model based on the current DPF flow resistance to determine the current basic carbon load;

[0009] querying a first preset MAP according to a current vehicle speed and a current vehicle acceleration to determine a first carbon load correction factor at a current moment;

[0010] querying a second preset MAP according to the current DPF temperature and the current nitrogen dioxide flow upstream of the DPF to determine a second carbon load correction factor at the current moment;

[0011] Determining a first carbon load correction factor at a current moment according to the first carbon load correction factor at a current moment and the second carbon load correction factor at a current moment;

[0012] The basic carbon loading at the current moment is corrected according to the first carbon loading correction coefficient at the current moment to obtain a first corrected carbon loading at the current moment, where the first corrected carbon loading at the current moment is equal to the product of the first carbon loading correction coefficient at the current moment and the basic carbon loading at the current moment.

[0013] Preferably, after determining the first carbon loading correction coefficient at the current moment, the method further includes:

[0014] Calculating a second carbon load correction coefficient at a current moment, where the second carbon load correction coefficient at the current moment is equal to an average value of the first carbon load correction coefficients within a preset time period up to the current moment;

[0015] The basic carbon loading at the current moment is corrected according to the second carbon loading correction coefficient at the current moment to obtain the second corrected carbon loading at the current moment. The second corrected carbon loading at the current moment is equal to the product of the second carbon loading correction coefficient at the current moment and the basic carbon loading at the current moment.

[0016] Preferably, the minimum value of the first carbon loading correction factor is not less than the maximum value of the second carbon loading correction factor;

[0017] Determining a first carbon loading correction factor at a current moment according to the first carbon loading correction factor at a current moment and the second carbon loading correction factor at a current moment includes:

[0018] Calculating the product of the first carbon load correction factor at the current moment and the second carbon load correction factor at the current moment;

[0019] If the product of the first carbon load correction factor at the current moment and the second carbon load correction factor at the current moment is not less than the preset threshold, the first carbon load correction factor at the current moment is equal to 1;

[0020] If the product of the first carbon loading correction factor at the current moment and the second carbon loading correction factor at the current moment is less than the preset threshold, the first carbon loading correction coefficient at the current moment is equal to the product of the first carbon loading correction factor at the current moment and the second carbon loading correction factor at the current moment.

[0021] Preferably, the first preset MAP includes a correspondence between vehicle speed, vehicle acceleration, and the first carbon load correction factor. In the first preset MAP, when the vehicle speed is constant, the first carbon load correction factor increases with increasing vehicle acceleration; when the vehicle acceleration is constant, the first carbon load correction factor decreases with increasing vehicle speed.

[0022] The second preset MAP includes the correspondence between the DPF temperature, the nitrogen dioxide flow rate upstream of the DPF, and the second carbon load correction factor. In the second preset MAP, when the DPF temperature is lower than the preset temperature, the second carbon load correction factor takes the maximum value. When the DPF temperature is not lower than the preset temperature, if the DPF temperature is constant, the second carbon load correction factor decreases with the increase of the nitrogen dioxide flow rate upstream of the DPF. If the nitrogen dioxide flow rate upstream of the DPF is constant, the second carbon load correction factor decreases with the increase of the DPF temperature.

[0023] Preferably, the current DPF temperature is the average temperature of the current DPF.

[0024] Preferably, before querying the second preset MAP according to the current DPF temperature and the current nitrogen dioxide flow rate upstream of the DPF, the method further includes determining the current DPF temperature;

[0025] Determining the current DPF temperature includes:

[0026] The current DPF average temperature is determined based on the current DPF inlet temperature and the current exhaust gas flow rate.

[0027] Preferably, before querying the second preset MAP according to the current DPF temperature and the current nitrogen dioxide flow rate upstream of the DPF, the method further includes determining the current nitrogen dioxide flow rate upstream of the DPF;

[0028] Determining the current nitrogen dioxide flow upstream of the DPF includes:

[0029] The current nitrogen oxide flow rate upstream of the DOC is calculated based on the current exhaust gas flow rate upstream of the DOC and the current nitrogen oxide concentration upstream of the DOC;

[0030] Querying a third preset MAP according to the current DOC temperature to obtain the current DOC to nitric oxide conversion efficiency;

[0031] According to the current DOC to nitric oxide conversion rate, calculate the proportion of nitrogen dioxide in the nitrogen oxides downstream of the current DOC;

[0032] The nitrogen dioxide flow rate upstream of the DPF is obtained according to the current nitrogen oxide flow rate upstream of the DOC and the ratio of nitrogen dioxide in the nitrogen oxides downstream of the DOC.

[0033] Preferably, the calculation of the first carbon loading correction factor is performed cyclically at preset time intervals.

[0034] The DPF status monitoring device monitors the carbon load of the DPF using any of the above-mentioned methods for determining the carbon load of the DPF.

[0035] A vehicle monitors the carbon load of a DPF using any of the above-mentioned methods for determining the carbon load of a DPF.

[0036] Beneficial effects of the present invention:

[0037] In the DPF carbon load determination method provided in this embodiment, vehicle speed and acceleration can characterize the exhaust gas particulate matter content. Without considering the carbon removal effect of regeneration, the higher the exhaust gas particulate matter content, the faster the DPF carbon load increases, while the lower the exhaust gas particulate matter content, the slower the DPF carbon load increases. DPF temperature and nitrogen dioxide flow upstream of the DPF can characterize the DPF passive regeneration rate. Higher DPF temperature and greater nitrogen dioxide flow upstream of the DPF indicate a faster passive regeneration rate. Lower DPF temperature and lower nitrogen dioxide flow upstream of the DPF indicate essentially no passive regeneration. Therefore, the first carbon load correction factor determined according to the vehicle speed and vehicle acceleration can reflect the rising rate of the DPF carbon load when the passive regeneration effect is not considered, and the second carbon load correction factor determined according to the DPF temperature and the nitrogen dioxide flow rate upstream of the DPF can reflect the passive regeneration carbon elimination rate. Furthermore, the first carbon load correction factor at the current moment determined by combining the first carbon load correction factor at the current moment with the second carbon load correction factor at the current moment can reflect whether the current DPF is generally in the carbon deposition stage or the carbon elimination stage, as well as the speed of carbon deposition or carbon elimination. In the DPF carbon deposition stage, the pressure differential carbon load model can accurately reflect the DPF carbon load, while in the DPF carbon elimination stage, the actual DPF carbon load is quite different from the DPF carbon load reflected by the pressure differential carbon load model. Therefore, the basic carbon load at the current moment is corrected according to the first carbon load correction factor at the current moment to obtain the first corrected carbon load. Compared with the basic carbon load, the first corrected carbon load is more accurate. BRIEF DESCRIPTION OF THE DRAWINGS

[0038] Figure 1 is a flow chart of a method for determining DPF carbon load provided in Example 1 of the present invention;

[0039] Figure 2 This is a flow chart of determining the first carbon loading correction coefficient at the current moment provided by the first embodiment of the present invention;

[0040] Figure 3 This is a schematic diagram of the relationship between vehicle speed, vehicle acceleration and particulate matter emissions provided by the first embodiment of the present invention;

[0041] Figure 4 Schematic diagram of the relationship between the average DPF temperature, nitrogen dioxide flow rate and passive regeneration rate provided in Example 1 of the present invention;

[0042] Figure 5 This is a flow chart for determining the current nitrogen dioxide flow upstream of the DPF provided in Example 1 of the present invention;

[0043] Figure 6This is a flow chart of a method for determining DPF carbon load provided in the second embodiment of the present invention. DETAILED DESCRIPTION

[0044] The present invention will be further described in detail below with reference to the accompanying drawings and examples. It will be understood that the specific embodiments described herein are intended only to illustrate the present invention and are not intended to limit the present invention. It should also be noted that, for ease of description, the accompanying drawings only illustrate portions relevant to the present invention, not all structures.

[0045] In the description of the present invention, unless otherwise expressly specified or limited, the terms "connected," "connected," and "fixed" should be understood in a broad sense. For example, they may refer to fixed connections, detachable connections, or integration; mechanical connections or electrical connections; direct connections or indirect connections through an intermediate medium; and internal communication between two components or interaction between two components. Those skilled in the art will understand the specific meanings of the above terms in the present invention in specific circumstances.

[0046] In the present invention, unless otherwise expressly specified or limited, a first feature being "above" or "below" a second feature may include the first and second features being in direct contact, or may include the first and second features being in contact not directly but through another feature between them. Furthermore, a first feature being "above," "above," and "above" a second feature may include the first feature being directly above or obliquely above the second feature, or may simply mean that the first feature is higher in level than the second feature. A first feature being "below," "below," and "below" a second feature may include the first feature being directly below or obliquely below the second feature, or may simply mean that the first feature is lower in level than the second feature.

[0047] In the description of this embodiment, the terms "upper," "lower," "right," and other orientations or positional relationships are based on the orientations or positional relationships shown in the accompanying drawings and are intended solely for ease of description and simplified operation. They do not indicate or imply that the devices or components referred to must have, be constructed, or operate in a specific orientation. Therefore, they should not be construed as limitations on the present invention. Furthermore, the terms "first" and "second" are used solely for descriptive purposes and have no special meanings.

[0048] like Figure 1As shown, this embodiment provides a method for determining DPF carbon loading, including: querying a pressure differential carbon loading model based on the current DPF flow resistance to determine the current base carbon loading. The method for determining the DPF flow resistance is common knowledge in the art and will not be described in detail here; querying a first preset map based on the current vehicle speed and current vehicle acceleration to determine a first carbon loading correction factor at the current moment; querying a second preset map based on the current DPF temperature and the current nitrogen dioxide flow upstream of the DPF to determine a second carbon loading correction factor at the current moment; determining a first carbon loading correction factor at the current moment based on the first carbon loading correction factor and the second carbon loading correction factor at the current moment; and correcting the current base carbon loading based on the first carbon loading correction factor to obtain a first corrected carbon loading at the current moment, the first corrected carbon loading at the current moment being equal to the product of the first carbon loading correction factor and the current base carbon loading at the current moment. Both the first preset map and the second preset map are obtained through bench testing.

[0049] In the DPF carbon load determination method provided in this embodiment, vehicle speed and acceleration can be used to characterize the particulate matter content in the exhaust gas (i.e., tail gas). Without considering the carbon removal effect of regeneration, the higher the particulate matter content in the exhaust gas, the faster the DPF carbon load increases, while the lower the particulate matter content in the exhaust gas, the slower the DPF carbon load increases. DPF temperature and the nitrogen dioxide flow rate upstream of the DPF can be used to characterize the DPF's passive regeneration rate. Higher DPF temperature and greater nitrogen dioxide flow rate upstream of the DPF indicate a faster passive regeneration rate. Lower DPF temperature and lower nitrogen dioxide flow rate upstream of the DPF indicate essentially no passive regeneration. It should be noted that passive regeneration is the process by which nitrogen dioxide oxidizes carbon deposits on the DPF. Therefore, the first carbon load correction factor determined according to the vehicle speed and vehicle acceleration can reflect the rising rate of the DPF carbon load when the passive regeneration effect is not considered, and the second carbon load correction factor determined according to the DPF temperature and the nitrogen dioxide flow rate upstream of the DPF can reflect the passive regeneration carbon elimination rate. Furthermore, the first carbon load correction factor at the current moment determined by combining the first carbon load correction factor at the current moment with the second carbon load correction factor at the current moment can reflect whether the current DPF is generally in the carbon deposition stage or the carbon elimination stage, as well as the speed of carbon deposition or carbon elimination. In the DPF carbon deposition stage, the pressure differential carbon load model can accurately reflect the DPF carbon load, while in the DPF carbon elimination stage, the actual DPF carbon load is quite different from the DPF carbon load reflected by the pressure differential carbon load model. Therefore, the basic carbon load at the current moment is corrected according to the first carbon load correction factor at the current moment to obtain the first corrected carbon load. Compared with the basic carbon load, the first corrected carbon load is more accurate.

[0050] Optionally, the calculation of the first carbon loading correction coefficient and the first corrected carbon loading is performed cyclically at preset time intervals.

[0051] Optionally, the minimum value of the first carbon loading correction factor is not less than the maximum value of the second carbon loading correction factor.

[0052] Furthermore, if Figure 2 As shown, determining the first carbon loading correction factor at the current moment according to the first carbon loading correction factor at the current moment and the second carbon loading correction factor at the current moment includes:

[0053] Calculating the product of the first carbon load correction factor at the current moment and the second carbon load correction factor at the current moment;

[0054] If the product of the first carbon load correction factor at the current moment and the second carbon load correction factor at the current moment is not less than the preset threshold, then the first carbon load correction factor at the current moment is equal to the preset threshold;

[0055] If the product of the first carbon loading correction factor at the current moment and the second carbon loading correction factor at the current moment is less than the preset threshold, the first carbon loading correction coefficient at the current moment is equal to the product of the first carbon loading correction factor at the current moment and the second carbon loading correction factor at the current moment.

[0056] In other words, the product of the first carbon load correction factor and the second carbon load correction factor is used as a characterization value to indicate whether the DPF is in the carbon deposition stage or the carbon elimination stage. If the product of the first carbon load correction factor and the second carbon load correction factor is less than a preset threshold, it indicates that the DPF is currently in the carbon elimination stage. When the DPF is in the carbon elimination stage, the basic carbon load obtained according to the pressure differential carbon load model cannot accurately reflect the current actual carbon load of the DPF, and the basic carbon load needs to be corrected. Therefore, the first carbon load correction factor is equal to the product of the first carbon load correction factor and the second carbon load correction factor. If the product of the first carbon load correction factor and the second carbon load correction factor is not less than the preset threshold, it indicates that the DPF is currently not in the carbon elimination stage. At this time, the basic carbon load obtained according to the pressure differential carbon load model can accurately reflect the current actual carbon load of the DPF. Therefore, the first carbon load correction factor is equal to 1, which means that the first corrected carbon load at the current moment is equal to the basic carbon load at the current moment.

[0057] Optionally, the first preset MAP includes a correspondence between vehicle speed, vehicle acceleration, and the first carbon load correction factor. In the first preset MAP, when the vehicle speed is constant, the first carbon load correction factor increases with the increase of vehicle acceleration; when the vehicle acceleration is constant, the first carbon load correction factor decreases with the increase of vehicle speed. The relationship between vehicle speed and vehicle acceleration and particulate matter emissions in exhaust gas is as follows: Figure 3As can be seen from the figure, the greater the acceleration and the smaller the vehicle speed, the higher the particulate matter emissions, and the higher the particulate matter emissions, the faster the DPF carbon deposition rate. Therefore, when the vehicle speed is constant, the first carbon load correction factor increases with the increase of vehicle acceleration. When the vehicle acceleration is constant, the first carbon load correction factor decreases with the increase of vehicle speed.

[0058] The second preset MAP includes the corresponding relationship between DPF temperature, DPF upstream nitrogen dioxide flow rate and the second carbon load correction factor. In the second preset MAP, when the DPF temperature is less than the preset temperature, the second carbon load correction factor takes the maximum value. When the DPF temperature is not less than the preset temperature, the second carbon load correction factor decreases with the increase of DPF upstream nitrogen dioxide flow rate. When the DPF upstream nitrogen dioxide flow rate is constant, the second carbon load correction factor decreases with the increase of DPF temperature. The relationship between DPF upstream nitrogen dioxide flow rate and DPF average temperature and passive regeneration rate is as follows: Figure 4 As shown in the figure, it can be seen that the higher the average DPF temperature, the greater the nitrogen dioxide flow rate upstream of the DPF, and the faster the DPF regeneration rate. However, when the average DPF temperature is lower than the oxidation temperature of carbon deposits on the DPF, passive regeneration does not occur. Therefore, when the DPF temperature is lower than a preset temperature, the second carbon loading coefficient reaches its maximum value. In this embodiment, the preset temperature is 250°C. When the DPF temperature is not lower than the preset temperature, the second correction coefficient decreases with increasing nitrogen dioxide flow rate upstream of the DPF, while the nitrogen dioxide flow rate upstream of the DPF is constant.

[0059] For example, in this embodiment, the minimum value of the first carbon loading correction factor is 1 and the maximum value is 3, the minimum value of the second carbon loading correction factor is 0.1 and the maximum value is 1, and the preset threshold value is 1. That is, when the product of the first carbon loading correction factor and the second carbon loading correction factor at the current moment is not less than 1, the first carbon loading correction factor at the current moment is equal to 1; when the product of the first carbon loading correction factor and the second carbon loading correction factor at the current moment is less than 1, the first carbon loading correction factor at the current moment is equal to the product of the first carbon loading correction factor and the second carbon loading correction factor at the current moment.

[0060] Optionally, the current DPF temperature is the current average temperature of the DPF.

[0061] Furthermore, before querying the second preset MAP based on the current DPF temperature and the current DPF upstream nitrogen dioxide flow, the current DPF temperature is also determined. Determining the current DPF temperature includes: determining the current DPF average temperature based on the current DPF inlet temperature and the current exhaust gas flow. Specifically, in this embodiment, the DPF average temperature MAP is queried based on the current DPF inlet temperature and the current exhaust gas flow to determine the current DPF average temperature. The DPF average temperature MAP includes the correspondence between the DPF inlet temperature, the exhaust gas flow and the DPF average temperature, and the DPF average temperature MAP is obtained through bench testing. In other embodiments, the heat dissipation parameters of the DPF can also be pre-stored on the vehicle, and the average temperature of the DPF can be calculated based on the DPF inlet temperature, the current exhaust gas flow and the heat dissipation parameters. The specific calculation method is a conventional technical means in this field and will not be repeated here.

[0062] Optionally, before querying the second preset MAP based on the current DPF temperature and the current DPF upstream nitrogen dioxide flow, the method further includes determining the current DPF upstream nitrogen dioxide flow. Figure 5 As shown, determining the current nitrogen dioxide flow includes:

[0063] The current nitrogen oxide flow rate upstream of the DOC is calculated based on the current exhaust gas flow rate upstream of the DOC and the current nitrogen oxide concentration upstream of the DOC. The nitrogen oxide concentration upstream of the DOC is measured by a sensor.

[0064] Querying a third preset MAP according to the current DOC temperature to obtain the current DOC to nitric oxide conversion efficiency;

[0065] According to the current DOC to nitric oxide conversion rate, calculate the proportion of nitrogen dioxide in the nitrogen oxides downstream of the current DOC;

[0066] The nitrogen dioxide flow rate upstream of the DPF is obtained according to the current nitrogen oxide flow rate upstream of the DOC and the ratio of nitrogen dioxide in the nitrogen oxides downstream of the DOC.

[0067] The third preset MAP is obtained through bench testing. In a vehicle's aftertreatment system, exhaust gas first passes through a DOC (oxidation catalytic converter), then a DPF (particulate matter filter), and finally an SCR (selective catalytic reduction). The operating principles of the DOC and SCR are common knowledge in the field and will not be elaborated upon here. It should be noted that since the nitrogen oxide concentration upstream of the DOC and the exhaust gas flow upstream of the DOC change slowly, the current exhaust gas flow upstream of the DOC and the current nitrogen oxide concentration upstream of the DOC can be used to calculate the ratio of nitrogen dioxide to the nitrogen oxides downstream of the DOC. Furthermore, the vast majority of nitrogen oxides upstream of the DOC are nitrogen monoxide, with very little nitrogen dioxide. Therefore, when calculating the ratio of nitrogen dioxide to nitrogen oxides downstream of the DOC, all nitrogen oxides upstream of the DOC are treated as nitrogen monoxide for subsequent calculations. This subsequent calculation is common knowledge in the field and will not be elaborated upon here.

[0068] Example 2

[0069] like Figure 6 As shown, this embodiment provides a method for determining the carbon load of a DPF, which is a further improvement of the method for determining the carbon load of a DPF in the first embodiment. The difference between this embodiment and the first embodiment is that after determining the first carbon load correction coefficient at the current moment, the method further includes:

[0070] Calculating a second carbon load correction coefficient at a current moment, where the second carbon load correction coefficient at the current moment is equal to an average value of the first carbon load correction coefficients within a preset time period up to the current moment;

[0071] The basic carbon loading at the current moment is corrected according to the second carbon loading correction coefficient at the current moment to obtain the second corrected carbon loading at the current moment. The second corrected carbon loading at the current moment is equal to the product of the second carbon loading correction coefficient at the current moment and the basic carbon loading at the current moment.

[0072] Since the pressure difference and DPF carbon load both change slowly during the carbon deposition process and the passive regeneration carbon removal process, and the vehicle speed, vehicle acceleration, DPF temperature, and nitrogen dioxide flow rate upstream of the DPF at a certain moment are instantaneous, the vehicle speed, vehicle acceleration, DPF temperature, and nitrogen dioxide flow rate upstream of the DPF at two adjacent moments may vary significantly due to certain reasons (such as sensor measurement errors). Therefore, to avoid sudden changes in the corrected DPF carbon load, this embodiment corrects the base carbon load at the current moment according to the second carbon load correction coefficient at the current moment to obtain a second corrected carbon load at the current moment. The second carbon load correction coefficient at the current moment is equal to the average value of the first carbon load correction coefficient within a preset time period up to the current moment, thereby avoiding sudden changes in the corrected DPF carbon load and causing the corrected DPF carbon load to change gradually over time. Compared with the first corrected carbon load, the second corrected carbon load is more accurate.

[0073] Optionally, the calculation of the second carbon loading correction coefficient and the second corrected carbon loading is performed cyclically at preset time intervals.

[0074] Example 3

[0075] This embodiment further provides a DPF status monitoring device, which uses the DPF carbon load determination method in any of the above embodiments to monitor the carbon load of the DPF.

[0076] This embodiment also provides a vehicle, which uses the DPF carbon load determination method in any of the above embodiments to monitor the carbon load of the DPF.

[0077] Obviously, the above embodiments of the present invention are merely examples for the purpose of clearly illustrating the present invention and are not intended to limit the embodiments of the present invention. A person skilled in the art would be able to make various obvious changes, readjustments, and substitutions without departing from the scope of protection of the present invention. It is not necessary and impossible to enumerate all embodiments here. Any modifications, equivalent substitutions, and improvements made within the spirit and principles of the present invention shall be included within the scope of protection of the claims of the present invention.

Claims

1. A method for determining DPF carbon load, characterized in that: include: Query the pressure difference carbon load model based on the current DPF flow resistance to determine the current basic carbon load; querying a first preset MAP according to a current vehicle speed and a current vehicle acceleration to determine a first carbon load correction factor at a current moment; querying a second preset MAP according to the current DPF temperature and the current nitrogen dioxide flow upstream of the DPF to determine a second carbon load correction factor at the current moment; Determining a first carbon load correction factor at a current moment according to the first carbon load correction factor at a current moment and the second carbon load correction factor at a current moment; Correcting the basic carbon loading at the current moment according to the first carbon loading correction coefficient at the current moment to obtain a first corrected carbon loading at the current moment, where the first corrected carbon loading at the current moment is equal to the product of the first carbon loading correction coefficient at the current moment and the basic carbon loading at the current moment; The minimum value of the first carbon load correction factor is not less than the maximum value of the second carbon load correction factor; Determining a first carbon loading correction factor at a current moment according to the first carbon loading correction factor at a current moment and the second carbon loading correction factor at a current moment includes: Calculating the product of the first carbon load correction factor at the current moment and the second carbon load correction factor at the current moment; If the product of the first carbon load correction factor at the current moment and the second carbon load correction factor at the current moment is not less than the preset threshold, the first carbon load correction factor at the current moment is equal to 1; If the product of the first carbon loading correction factor at the current moment and the second carbon loading correction factor at the current moment is less than the preset threshold, the first carbon loading correction coefficient at the current moment is equal to the product of the first carbon loading correction factor at the current moment and the second carbon loading correction factor at the current moment.

2. The method for determining DPF carbon load according to claim 1, characterized in that: After determining the first carbon load correction coefficient at the current moment, the following steps are also included: Calculating a second carbon load correction coefficient at a current moment, where the second carbon load correction coefficient at the current moment is equal to an average value of the first carbon load correction coefficients within a preset time period up to the current moment; The basic carbon loading at the current moment is corrected according to the second carbon loading correction coefficient at the current moment to obtain the second corrected carbon loading at the current moment. The second corrected carbon loading at the current moment is equal to the product of the second carbon loading correction coefficient at the current moment and the basic carbon loading at the current moment.

3. The method for determining DPF carbon load according to claim 1, characterized in that: The first preset MAP includes a correspondence between vehicle speed, vehicle acceleration, and a first carbon load correction factor. In the first preset MAP, if the vehicle speed is constant, the first carbon load correction factor increases with increasing vehicle acceleration; if the vehicle acceleration is constant, the first carbon load correction factor decreases with increasing vehicle speed. The second preset MAP includes the correspondence between the DPF temperature, the nitrogen dioxide flow rate upstream of the DPF, and the second carbon load correction factor. In the second preset MAP, when the DPF temperature is lower than the preset temperature, the second carbon load correction factor takes the maximum value. When the DPF temperature is not lower than the preset temperature, if the DPF temperature is constant, the second carbon load correction factor decreases with the increase of the nitrogen dioxide flow rate upstream of the DPF. If the nitrogen dioxide flow rate upstream of the DPF is constant, the second carbon load correction factor decreases with the increase of the DPF temperature.

4. The method for determining DPF carbon load according to any one of claims 1 to 2, characterized in that: The current DPF temperature is the current average temperature of the DPF.

5. The method for determining DPF carbon load according to claim 4, characterized in that: Before querying the second preset MAP based on the current DPF temperature and the current nitrogen dioxide flow rate upstream of the DPF, the method further includes determining the current DPF temperature; Determining the current DPF temperature includes: The current DPF average temperature is determined based on the current DPF inlet temperature and the current exhaust gas flow rate.

6. The method for determining DPF carbon load according to any one of claims 1-2, characterized in that: Before querying the second preset MAP according to the current DPF temperature and the current nitrogen dioxide flow rate upstream of the DPF, the method further includes determining the current nitrogen dioxide flow rate upstream of the DPF; Determining the current nitrogen dioxide flow upstream of the DPF includes: The current nitrogen oxide flow rate upstream of the DOC is calculated based on the current exhaust gas flow rate upstream of the DOC and the current nitrogen oxide concentration upstream of the DOC; Querying a third preset MAP according to the current DOC temperature to obtain the current DOC to nitric oxide conversion efficiency; According to the current DOC to nitric oxide conversion rate, calculate the proportion of nitrogen dioxide in the nitrogen oxides downstream of the current DOC; The nitrogen dioxide flow rate upstream of the DPF is obtained according to the current nitrogen oxide flow rate upstream of the DOC and the ratio of nitrogen dioxide in the nitrogen oxides downstream of the DOC.

7. The method for determining DPF carbon load according to any one of claims 1 to 2, characterized in that: The first carbon loading correction factor calculation is performed cyclically at preset time intervals. 8.DPF status monitoring device, characterized in that, The carbon load of the DPF is monitored using the DPF carbon load determination method according to any one of claims 1 to 7.

9. A vehicle, characterized in that The carbon load of the DPF is monitored using the DPF carbon load determination method according to any one of claims 1 to 7.

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