Method for diagnosing overload of particulate filter, diagnostic device and vehicle

Abstract

The application provides a method and device for diagnosing overload of a particulate filter and a vehicle, the method comprising: obtaining a current mileage, obtaining a target regeneration threshold and a target alarm threshold according to the target mapping relationship obtained by querying the target mapping relationship according to the current mileage; obtaining a corrected differential pressure; in the case that the corrected differential pressure is greater than or equal to the target regeneration threshold and less than the target alarm threshold, controlling the particulate filter to regenerate, in the case that the corrected differential pressure is less than the target regeneration threshold, controlling the particulate filter not to regenerate, and in the case that the corrected differential pressure is greater than or equal to the target alarm threshold, issuing a first alarm information, the first alarm information being used for prompting that the particulate filter needs to be cleaned, and the target alarm threshold being greater than the target regeneration threshold. The method solves the problem that in the prior art, when the overload differential pressure limit value is limited, the differential pressure change caused by the change of the particulate filter ash accumulation state is not considered, resulting in inaccurate judgment.

Description

Technical Field

[0001] This invention relates to the field of data communication technology, and more specifically, to a diagnostic method, diagnostic device, computer-readable storage medium, and vehicle for particulate filter overload. Background Technology

[0002] The carbon deposition process in DPF (Digital Pore Filter) involves the initial accumulation of carbon soot in the upper half of its micropores. This process is called "deep bed filtration" of carbon particles, and the captured particles are called the "deep bed soot." Once the deep bed soot has accumulated to a certain extent, carbon deposition ceases within the micropores. Subsequent carbon particles accumulate on the upper wall of the DPF micropores, forming a layer. This trapping process is called "cake trapping" or "cake layer trapping," and the corresponding carbon layer outside the micropores is called the "cake soot." Both types of carbon layers can be consumed during active and passive regeneration.

[0003] When the DPF has been used for a long time and ash particles accumulate, because the particle size of ash particles is larger than that of carbon particles, it is difficult for them to enter the micropores to form a deep bed. Generally, they can only form an "ash cake layer" outside the pores or an "ash blockage" at the end of the inlet channel. Furthermore, the ash cannot be removed by active or passive regeneration and will remain in the DPF. When carbon particles enter at this time, the ash cake layer further hinders their entry, making it difficult for carbon particles to form a deep bed carbon layer, and instead, they tend to form a filter cake carbon layer directly. The effects of deep bed carbon layers and filter cake carbon layers on the DPF pressure differential are different. Overall, the DPF pressure differential increases with the increase of carbon loading. However, it varies in stages: initially, when deep bed collection occurs, the rate of change of pressure differential is high, and the pressure differential increases rapidly and non-linearly; later, when cake layer collection occurs, the rate of change of pressure differential is constant, and the pressure differential increases linearly and steadily. Even when the DPF is ash-free after ash accumulation, the pressure differential is slightly higher than when it is fresh and ash-free due to the presence of ash. When carbon is deposited again at this point, the ash content hinders the entry of carbon particles into the micropores, making deep bed trapping difficult and resulting in direct cake-layer trapping. Therefore, as the carbon loading increases, the pressure difference maintains a stable linear increase. Ultimately, within a certain carbon loading range, the pressure difference of a DPF with ash content may be slightly lower than that of a DPF without ash content. This characteristic is called the film effect of DPF pressure difference.

[0004] Existing methods in the industry that identify carbon load and indicate overload based on DPF differential pressure do not consider the influence of the film layer effect on the differential pressure. They only calibrate the parameters when the engine is in a fresh state to obtain the differential pressure threshold under overload conditions. However, after the DPF has been used for a long time, the differential pressure corresponding to the same carbon load will change due to the influence of the film layer effect, which will lead to false alarms or missed faults. Summary of the Invention

[0005] The main objective of this application is to provide a diagnostic method, diagnostic device, computer-readable storage medium, and vehicle for particulate filter overload, so as to at least solve the problem that the prior art does not consider the pressure difference caused by the change in the dust accumulation state of the particulate filter when limiting the overload pressure difference limit, resulting in inaccurate judgment.

[0006] To achieve the above objectives, according to one aspect of this application, a method for diagnosing particulate filter overload is provided. The exhaust port of an engine is connected to the intake port of the particulate filter, which is used to treat the engine's exhaust gas. The method includes: acquiring a current mileage; querying a target mapping relationship based on the current mileage to obtain a target regeneration threshold and a target alarm threshold; the target regeneration threshold and the target alarm threshold are a regeneration threshold and an alarm threshold corresponding to the current mileage; the current mileage is the total mileage traveled by the engine from a first moment to the current moment; the first moment is the moment when dust removal ends; and the target mapping relationship is a mapping relationship between the total mileage and the regeneration threshold and the alarm threshold. The system obtains a corrected differential pressure, which is obtained by eliminating the differential pressure error caused by changes in exhaust gas velocity based on the filtration differential pressure monitored by the pressure sensor. The filtration differential pressure is the pressure difference between the air pressure at the inlet and outlet of the particulate filter. When the corrected differential pressure is greater than or equal to the target regeneration threshold and less than the target alarm threshold, the system controls the particulate filter to regenerate. When the corrected differential pressure is less than the target regeneration threshold, the system controls the particulate filter not to regenerate. When the corrected differential pressure is greater than or equal to the target alarm threshold, the system issues a first alarm message, which is used to prompt the particulate filter to be cleaned. The target alarm threshold is greater than the target regeneration threshold.

[0007] Optionally, before obtaining the target regeneration threshold and target alarm threshold by querying the target mapping relationship based on the current mileage, the method further includes: a first acquisition step, acquiring a first curve, a second curve, and a third curve, wherein the first curve is a curve showing the change of overload pressure difference with the total mileage, the second curve is a curve showing the change of ash accumulation pressure difference with the total mileage, the overload pressure difference is the filtration pressure difference of the particulate filter when the carbon load in the particulate filter reaches a first preset value, the ash accumulation pressure difference is the filtration pressure difference of the particulate filter after controlling the particulate filter to regenerate, and the third curve is a curve showing the change of ash accumulation in the particulate filter with the ash accumulation pressure difference after controlling the particulate filter to regenerate; a second acquisition step, a target driving mileage range, calculating the average value of all ash accumulation pressure differences within the target driving mileage range based on the target driving mileage range and the second curve to obtain a first pressure difference, wherein the target driving mileage range is any one of the preset driving mileage ranges; a first determination step, determining the target based on the first pressure difference and the third curve. The target ash accumulation amount is the ash accumulation amount corresponding to the first pressure difference in the third curve; the third acquisition step is to acquire a fourth curve based on the target ash accumulation amount, the fourth curve being a curve showing the change of the filtration pressure difference with the carbon loading when the ash accumulation amount in the particulate filter is the target ash accumulation amount; the second determination step is to determine a regeneration threshold and an alarm threshold based on a first preset carbon loading, a second preset carbon loading, and the fourth curve, the regeneration threshold being the filtration pressure difference corresponding to the first preset carbon loading in the fourth curve, and the alarm threshold being the filtration pressure difference corresponding to the second preset carbon loading in the fourth curve, wherein the first preset carbon loading is greater than the second preset carbon loading; the second acquisition step, the first determination step, the third acquisition step, and the second determination step are repeated at least once in sequence until the regeneration threshold and the alarm threshold corresponding to all preset driving mileage intervals are obtained; the target mapping relationship is constructed based on the correspondence between each preset driving mileage interval, each regeneration threshold, and each alarm threshold.

[0008] Optionally, obtaining the target regeneration threshold and the target alarm threshold by querying the target mapping relationship based on the current mileage includes: determining the preset driving mileage interval to which the current mileage belongs based on the current mileage; querying the regeneration threshold and the alarm threshold corresponding to the preset driving mileage interval to which the current mileage belongs in the target mapping relationship based on the preset driving mileage interval to which the current mileage belongs, and obtaining the target regeneration threshold and the alarm threshold.

[0009] Optionally, obtaining the corrected differential pressure includes: obtaining the current differential pressure, the current exhaust flow rate, and the preset exhaust flow rate, wherein the current differential pressure is the filter differential pressure at the current moment, and the current exhaust flow rate is the exhaust flow rate of the engine at the current moment; calculating the product of the current differential pressure and the preset exhaust flow rate, and calculating the quotient of the product divided by the current exhaust flow rate to obtain the corrected differential pressure.

[0010] Optionally, after obtaining the current mileage, the method further includes: obtaining identification information, the identification information including first identification information and second identification information, the first identification information being used to indicate whether the particulate filter has been cleaned, and the second identification information being used to indicate whether the particulate filter has been replaced; if the second identification information indicates that the particulate filter has been replaced, the current mileage is reset to zero; if the second identification information indicates that the particulate filter has not been replaced and the first identification information indicates that the particulate filter has been cleaned, an equivalent mileage is determined based on the current pressure difference and the second curve, and the current mileage is updated to the equivalent mileage, the equivalent mileage being the mileage corresponding to the current pressure difference in the second curve; if the second identification information indicates that the particulate filter has not been replaced and the first identification information indicates that the particulate filter has not been cleaned, the current mileage remains unchanged.

[0011] Optionally, before obtaining the current mileage, the method further includes: obtaining current operating condition parameters, wherein the current operating condition parameters are the operating condition parameters at the current moment, and the operating condition parameters include the engine speed, the engine torque, the engine exhaust temperature, and the signal from the differential pressure sensor; determining whether the current operating condition parameters meet a first condition, wherein the first condition is that the engine speed is within a first range, the torque is within a second range, and the exhaust temperature is within a third range; determining whether the current operating condition parameters meet a second condition, wherein the second condition is that the signal is within a fourth range and the rate of change of the signal is less than a second preset value; allowing the acquisition of the current mileage if both the first and second conditions are met; and disallowing the acquisition of the current mileage if either the first or second condition is not met.

[0012] Optionally, after obtaining the current pressure difference, the method further includes: issuing a second alarm message when the current pressure difference is less than a third preset value, the second alarm message being used to indicate that the particulate filter has melted.

[0013] According to another aspect of this application, a diagnostic device for particulate filter overload is provided, wherein the exhaust port of an engine is connected to the intake port of the particulate filter, the particulate filter being used to treat the exhaust gas of the engine, the device comprising: a first acquisition unit, configured to acquire the current mileage, and query a target mapping relationship based on the current mileage to obtain a target regeneration threshold and a target alarm threshold, wherein the target regeneration threshold and the target alarm threshold are regeneration threshold and alarm threshold corresponding to the current mileage, the current mileage being the total mileage traveled by the engine from a first moment to the current moment, the first moment being the moment when dust cleaning ends, and the target mapping relationship being the mapping relationship between the total mileage and the regeneration threshold and the alarm threshold; and a second acquisition unit, configured to acquire... The unit is used to obtain a corrected differential pressure, which is obtained by eliminating the differential pressure error caused by changes in exhaust gas velocity based on the filtration differential pressure monitored by the pressure sensor. The filtration differential pressure is the pressure difference between the air pressure at the inlet and outlet of the particulate filter. A first alarm unit is used to control the particulate filter to regenerate when the corrected differential pressure is greater than or equal to the target regeneration threshold and less than the target alarm threshold; to control the particulate filter not to regenerate when the corrected differential pressure is less than the target regeneration threshold; and to issue a first alarm message when the corrected differential pressure is greater than or equal to the target alarm threshold. The first alarm message is used to prompt the particulate filter to be cleaned, and the target alarm threshold is greater than the target regeneration threshold.

[0014] According to another aspect of this application, a computer-readable storage medium is provided, the computer-readable storage medium including a stored program, wherein, when the program is executed, it controls the device on which the computer-readable storage medium is located to perform any of the methods described.

[0015] According to another aspect of this application, a vehicle is provided, comprising: one or more processors, a memory, and one or more programs, wherein the one or more programs are stored in the memory and configured to be executed by the one or more processors, the one or more programs including methods for any one of the methods.

[0016] Applying the technical solution of this application, in the above-mentioned diagnostic method for particulate filters, firstly, the current mileage is obtained; based on the current mileage, a target mapping relationship is queried to obtain a target regeneration threshold and a target alarm threshold. The target regeneration threshold and the target alarm threshold are the regeneration threshold and alarm threshold corresponding to the current mileage, respectively. The current mileage is the total mileage traveled by the engine from a first moment to the current moment, where the first moment is the moment when dust removal ends. The target mapping relationship is the mapping relationship between the total mileage and the regeneration threshold and the alarm threshold. Then, a correction pressure difference is obtained, which is the filter pressure difference monitored by the pressure sensor. The pressure difference is obtained after eliminating the pressure difference error caused by changes in exhaust gas velocity. The aforementioned filtration pressure difference is the pressure difference between the air pressure at the inlet and outlet of the particulate filter. Finally, if the aforementioned corrected pressure difference is greater than or equal to the aforementioned target regeneration threshold and less than the aforementioned target alarm threshold, the particulate filter is controlled to regenerate. If the aforementioned corrected pressure difference is less than the aforementioned target regeneration threshold, the particulate filter is controlled not to regenerate. If the aforementioned corrected pressure difference is greater than or equal to the aforementioned target alarm threshold, a first alarm message is issued. The first alarm message is used to prompt the particulate filter to be cleaned. The aforementioned target alarm threshold is greater than the aforementioned target regeneration threshold. This application calibrates the actual pressure difference when the carbon load reaches the limit and the actual pressure difference when overloaded in different driving mileage segments. When making a judgment, based on the driving mileage segment where the total mileage is located, the corresponding regeneration threshold and alarm threshold are consulted. Based on the current corrected pressure difference, it is compared with the threshold to determine whether to regenerate or issue an alarm. Compared with the prior art, this application takes into account the impact of pressure difference changes when the carbon load reaches the limit or is overloaded due to dust accumulation in the particulate filter during driving on the overload judgment and the activation of the regeneration function. It solves the problem that the prior art does not consider the pressure difference changes caused by the change in the dust accumulation state of the particulate filter when limiting the overload pressure difference limit, which leads to inaccurate judgment. Attached Figure Description

[0017] Figure 1 A hardware block diagram of a mobile terminal for diagnosing particulate filter overload according to an embodiment of this application is shown.

[0018] Figure 2 A schematic flowchart of a method for diagnosing particulate filter overload according to an embodiment of this application is shown.

[0019] Figure 3 A schematic diagram of the initial state of a particulate filter according to an embodiment of this application is shown;

[0020] Figure 4 A schematic diagram of the structure of a particulate filter provided according to an embodiment of this application after operating for a period of time is shown;

[0021] Figure 5 The graphs showing the overload pressure differential and ash accumulation pressure differential of a particulate filter provided according to an embodiment of this application as a function of operating mileage are shown.

[0022] Figure 6 A flowchart illustrating a specific method for diagnosing particulate filter overload according to an embodiment of this application is shown.

[0023] Figure 7 A structural block diagram of a diagnostic device for particulate filter overload provided according to an embodiment of this application is shown.

[0024] The above figures include the following reference numerals:

[0025] 102. Processor; 104. Memory; 106. Transmission device; 108. Input / output device. Detailed Implementation

[0026] It should be noted that, unless otherwise specified, the embodiments and features described in this application can be combined with each other. This application will now be described in detail with reference to the accompanying drawings and embodiments.

[0027] To enable those skilled in the art to better understand the present application, the technical solutions in the embodiments of the present application will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of the present application, and not all embodiments. Based on the embodiments in the present application, all other embodiments obtained by those of ordinary skill in the art without creative effort should fall within the scope of protection of the present application.

[0028] It should be noted that the terms "first," "second," etc., in the specification, claims, and accompanying drawings of this application are used to distinguish similar objects and are not necessarily used to describe a specific order or sequence. It should be understood that such data can be interchanged where appropriate for the embodiments of this application described herein. Furthermore, the terms "comprising" and "having," and any variations thereof, are intended to cover non-exclusive inclusion; for example, a process, method, system, product, or apparatus that comprises a series of steps or units is not necessarily limited to those steps or units explicitly listed, but may include other steps or units not explicitly listed or inherent to such processes, methods, products, or apparatus.

[0029] For ease of description, the following explains some of the nouns or terms used in the embodiments of this application:

[0030] DPF stands for Diesel Particulate Filter, a key component used in diesel engine emission treatment. It's one of the methods for removing particulate matter. The DPF has a wall-flow structure; diesel engine exhaust containing particles flows through the DPF's inlet channel into its porous wall surface and then out through the outlet channel. During this process, most particles in the airflow are captured and retained on the DPF wall, thus purifying the particulate matter in the diesel engine exhaust.

[0031] DPF regeneration: At higher temperatures, carbon soot in the DPF can be gradually removed through chemical action. The relevant chemical reactions include the reaction of carbon with nitrogen dioxide in engine exhaust to produce nitrogen and carbon dioxide (called passive regeneration, with a slightly lower reaction temperature); and the reaction of carbon with oxygen in engine exhaust to produce carbon dioxide (called active regeneration, with a higher reaction temperature, equivalent to directly igniting the carbon).

[0032] Dust buildup in the DPF: Due to impurities in fuel, engine oil, and intake air, as well as wear and tear on moving engine parts, particulate matter produced by engine combustion includes not only combustible carbon particles but also non-combustible ash (mainly composed of calcium, phosphorus, zinc, and magnesium). Similar to carbon particles, the accumulation of ash also leads to a gradual increase in the DPF pressure differential (although the specific process differs slightly, see Section 5.1 for analysis), but ash accumulation is much slower than carbon particle accumulation. Furthermore, the non-combustible nature of ash means it cannot be purified through the aforementioned "regeneration" methods. When excessive dust buildup causes an excessively large pressure differential, the only solution is to remove the DPF and blow air or spray water against the original airflow direction to remove or flush out the ash particles.

[0033] As described in the background section, existing methods for identifying carbon load and indicating overload based on DPF differential pressure do not consider the influence of the membrane effect on the differential pressure. They only calibrate the parameters when the engine is in a fresh state to obtain the differential pressure threshold for the overload state. However, after the DPF has been used for a long time, the differential pressure corresponding to the same carbon load will change due to the influence of the membrane effect, which will lead to false alarms or missed alarms. In order to solve the problem that the existing technology does not consider the changes in differential pressure caused by the change of dust accumulation in the particulate filter when limiting the overload differential pressure limit, resulting in inaccurate judgment, the embodiments of this application provide a diagnostic method, diagnostic device, computer-readable storage medium, and vehicle for particulate filter overload.

[0034] The technical solutions of the present invention will be clearly and completely described below with reference to the accompanying drawings in the embodiments of the present invention.

[0035] The methods and embodiments provided in this application can be executed on a mobile terminal, computer terminal, or similar computing device. Taking running on a mobile terminal as an example, Figure 1 This is a hardware structure block diagram of a mobile terminal for a particulate filter overload diagnosis method according to an embodiment of the present invention. Figure 1 As shown, a mobile terminal may include one or more ( Figure 1 Only one is shown in the diagram. A processor 102 (which may include, but is not limited to, a microprocessor MCU or a programmable logic device FPGA, etc.) and a memory 104 for storing data are also shown. The mobile terminal may further include a transmission device 106 for communication functions and an input / output device 108. Those skilled in the art will understand that... Figure 1 The structure shown is for illustrative purposes only and does not limit the structure of the mobile terminal described above. For example, the mobile terminal may also include components that are more... Figure 1 The more or fewer components shown, or having the same Figure 1 The different configurations shown.

[0036] The memory 104 can be used to store computer programs, such as application software programs and modules, like the computer program corresponding to the device information display method in this embodiment of the invention. The processor 102 executes various functional applications and data processing by running the computer program stored in the memory 104, thereby implementing the above-described method. The memory 104 may include high-speed random access memory and non-volatile memory, such as one or more magnetic storage devices, flash memory, or other non-volatile solid-state memory. In some instances, the memory 104 may further include memory remotely located relative to the processor 102, and these remote memories can be connected to the mobile terminal via a network. Examples of the aforementioned networks include, but are not limited to, the Internet, corporate intranets, local area networks, mobile communication networks, and combinations thereof. The transmission device 106 is used to receive or send data via a network. Specific examples of the aforementioned networks may include wireless networks provided by the mobile terminal's communication provider. In one example, the transmission device 106 includes a network interface controller (NIC), which can be connected to other network devices via a base station to communicate with the Internet. In one example, the transmission device 106 may be a radio frequency (RF) module, which is used to communicate with the Internet wirelessly.

[0037] This embodiment provides a diagnostic method for particulate filter overload running on a mobile terminal, computer terminal, or similar computing device. It should be noted that the steps shown in the flowchart in the accompanying drawings can be executed in a computer system such as a set of computer-executable instructions. Although a logical order is shown in the flowchart, in some cases, the steps shown or described may be executed in a different order than that shown here.

[0038] Figure 2 This is a flowchart of a particulate filter overload diagnosis method according to an embodiment of this application. Figure 2 As shown, the method includes the following steps:

[0039] Step S201: Obtain the current mileage, and query the target mapping relationship based on the current mileage to obtain the target regeneration threshold and the target alarm threshold. The target regeneration threshold and the target alarm threshold are the regeneration threshold and alarm threshold corresponding to the current mileage. The current mileage is the total mileage traveled by the engine from the first moment to the current moment. The first moment is the moment when the dust cleaning ends. The target mapping relationship is the mapping relationship between the total mileage and the regeneration threshold and the alarm threshold.

[0040] Specifically, the initial state of the DPF is as follows: Figure 3 As shown. Figure 4 As shown, as engine mileage increases, ash cakes or ash plugs form in the DPF, reducing regeneration efficiency and decreasing pressure differential when the DPF is full of carbon. In one embodiment of this application, the engine mileage is divided into different driving ranges, and carbon load overload limits and carbon load regeneration limits are calibrated accordingly, thus obtaining the above-mentioned target mapping relationship. When making a judgment, the mapping relationship is queried based on the current mileage to obtain the overload pressure differential threshold and regeneration pressure differential threshold of the corresponding DPF current ash accumulation state, which are the above-mentioned target regeneration threshold and target alarm threshold.

[0041] Step S202: Obtain the corrected pressure difference. The corrected pressure difference is obtained by eliminating the pressure difference error caused by the change in exhaust gas flow rate based on the filter pressure difference monitored by the pressure sensor. The filter pressure difference is the pressure difference between the air inlet and outlet of the particulate filter.

[0042] Specifically, in order to ensure the accuracy of the diagnostic results, the actual pressure difference currently being monitored is normalized to obtain the above-mentioned corrected pressure difference, which removes the influence of different flow velocities on the pressure difference and ensures that the change in pressure difference is entirely caused by the change in carbon loading.

[0043] Step S203: When the corrected pressure difference is greater than or equal to the target regeneration threshold and less than the target alarm threshold, control the particulate filter to regenerate; when the corrected pressure difference is less than the target regeneration threshold, control the particulate filter not to regenerate; when the corrected pressure difference is greater than or equal to the target alarm threshold, issue a first alarm message. The first alarm message is used to prompt the particulate filter to be cleaned. The target alarm threshold is greater than the target regeneration threshold.

[0044] Specifically, the corrected pressure difference is compared with the target regeneration threshold and the target alarm threshold. If the corrected pressure difference exceeds the regeneration threshold, it is determined that the carbon load meets the regeneration requirements, and the DPF is controlled to regenerate. If the corrected pressure difference exceeds the alarm threshold, it is determined that the carbon load has reached the overload limit. At this time, the ECU issues the first alarm message, prompting the driver that the DPF cannot regenerate and that they need to find the nearest service station for cleaning.

[0045] In this embodiment, firstly, the current mileage is obtained. Based on the current mileage, the target regeneration threshold and target alarm threshold are obtained by querying the target mapping relationship. The target regeneration threshold and target alarm threshold are the regeneration threshold and alarm threshold corresponding to the current mileage. The current mileage is the total mileage traveled by the engine from the first moment to the current moment. The first moment is the moment when the dust cleaning ends. The target mapping relationship is the mapping relationship between the total mileage and the regeneration threshold and the alarm threshold. Then, the corrected pressure difference is obtained. The corrected pressure difference is obtained after eliminating the pressure difference error caused by the change in exhaust gas velocity based on the filter pressure difference monitored by the pressure sensor. The filter pressure difference is the pressure difference between the air pressure at the air inlet and air outlet of the particulate filter. Finally, if the corrected pressure difference is greater than or equal to the target regeneration threshold and less than the target alarm threshold, the particulate filter is controlled to regenerate. If the corrected pressure difference is less than the target regeneration threshold, the particulate filter is controlled not to regenerate. If the corrected pressure difference is greater than or equal to the target alarm threshold, a first alarm message is issued. The first alarm message is used to prompt the particulate filter to be cleaned. The target alarm threshold is greater than the target regeneration threshold. This application calibrates the actual pressure difference when carbon load reaches the limit and the actual pressure difference when overloaded in different driving mileage segments. When making a judgment, it consults the corresponding regeneration threshold and alarm threshold based on the driving mileage segment where the total mileage is located, and compares the current corrected pressure difference with the threshold to determine whether to perform regeneration or issue an alarm. Compared with existing technologies, this application considers the impact of pressure difference changes caused by particulate filter dust accumulation during driving on overload judgment and the activation of the regeneration function. This solves the problem in existing technologies that do not consider pressure difference changes caused by particulate filter dust accumulation when limiting overload pressure difference limits, leading to inaccurate judgments.

[0046] To obtain the regeneration threshold and alarm threshold corresponding to different mileage ranges, in an optional embodiment, before obtaining the target regeneration threshold and target alarm threshold by querying the target mapping relationship based on the current mileage, the method further includes:

[0047] Step S301, first acquisition step, acquiring a first curve, a second curve and a third curve, wherein the first curve is the curve of overload pressure difference changing with the total mileage, the second curve is the curve of ash accumulation pressure difference changing with the total mileage, the overload pressure difference is the filtration pressure difference of the particulate filter when the carbon load in the particulate filter reaches a first preset value, the ash accumulation pressure difference is the filtration pressure difference of the particulate filter after controlling the particulate filter to regenerate, and the third curve is the curve of ash accumulation in the particulate filter changing with the ash accumulation pressure difference after controlling the particulate filter to regenerate.

[0048] Specifically, such as Figure 5 As shown, curve B is the first curve mentioned above, and curve A is the second curve mentioned above. It can be seen that as the mileage increases, even when reaching full load, the pressure difference of the DPF decreases due to the membrane effect, while the pressure difference of the ash accumulation increases because the proportion of ash in the carbon load gradually increases, resulting in more ash that cannot be removed after regeneration. To explore the relationship between ash content and pressure difference, a third curve was plotted based on the second curve.

[0049] Step S302, second acquisition step, target driving mileage range, calculate the average value of all the above-mentioned dust accumulation pressure differences in the target driving range according to the above-mentioned target driving mileage range and the above-mentioned second curve to obtain the first pressure difference, the above-mentioned target driving mileage range is any one of the preset driving mileage ranges;

[0050] Specifically, to accurately determine whether the DPF is overloaded, in one embodiment of this application, the overload pressure difference and regeneration pressure difference are calibrated for different mileage intervals throughout the DPF's entire lifespan. The lifespan is expressed in terms of mileage. Any interval is then obtained to obtain the target mileage interval. Furthermore, based on the target mileage interval, a corresponding segment is extracted from the second curve, and the average value of the ash accumulation pressure difference within that interval is calculated to obtain the first pressure difference.

[0051] Step S303, first determination step, determine the target ash accumulation amount based on the first pressure difference and the third curve, wherein the target ash accumulation amount is the ash accumulation amount corresponding to the first pressure difference in the third curve;

[0052] Specifically, the calibrated value is obtained by calibrating the third curve based on the first pressure difference, which is the target ash accumulation amount.

[0053] Step S304, the third acquisition step, obtaining a fourth curve based on the target ash accumulation amount, the fourth curve being the curve of the change of the filtration pressure difference with the carbon loading when the ash accumulation amount in the particulate filter is the target ash accumulation amount.

[0054] In one embodiment of this application, the pressure difference changes with the carbon load due to the different initial ash accumulation. During the engine bench test, the relationship between the filter pressure difference and the carbon load corresponding to different initial ash accumulation is calibrated to obtain the above-mentioned fourth curve corresponding to different initial ash accumulation.

[0055] Specifically, the ECU retrieves the fourth curve stored in the ECU based on the target dust accumulation amount obtained from the calibration, thus obtaining the fourth curve corresponding to the target dust accumulation amount.

[0056] Step S305, the second determination step, determines the regeneration threshold and the alarm threshold based on the first preset carbon load, the second preset carbon load and the fourth curve mentioned above. The regeneration threshold is the filter pressure difference corresponding to the first preset carbon load in the fourth curve, and the alarm threshold is the filter pressure difference corresponding to the second preset carbon load in the fourth curve. The first preset carbon load is greater than the second preset carbon load.

[0057] Specifically, after obtaining the fourth curve showing the change of filtration differential pressure with carbon load in the current interval, the fourth curve is calibrated according to the overload limit and regeneration limit of carbon load to obtain the regeneration differential pressure threshold and alarm differential pressure threshold corresponding to the threshold, that is, the above-mentioned regeneration threshold and alarm threshold are obtained.

[0058] Step S306: Repeat the above-mentioned second acquisition step, the above-mentioned first determination step, the above-mentioned third acquisition step and the above-mentioned second determination step at least once, until the above-mentioned regeneration threshold and the above-mentioned alarm threshold corresponding to all the above-mentioned preset driving mileage intervals are obtained.

[0059] Specifically, the second acquisition step, the first determination step, the third acquisition step, and the second determination step described above are repeated in sequence to determine the regeneration threshold and the alarm threshold corresponding to each of the above driving mileage intervals.

[0060] Step S307: Construct the target mapping relationship based on the correspondence between each of the preset driving mileage ranges, each of the regeneration thresholds and each of the alarm thresholds.

[0061] Specifically, based on the correspondence between the preset driving mileage range, the regeneration threshold, and the alarm threshold, the data is written into the corresponding positions in the table and stored in the ECU, thus obtaining the target mapping relationship.

[0062] It is important to note that, in order to ensure that the calibration results are not affected by random errors during the calibration process, after obtaining the above regeneration threshold and alarm threshold, the first curve will be calibrated according to the upper limit of the mileage in the corresponding interval to obtain the corresponding verification pressure difference. If the alarm threshold is less than the verification pressure difference, it is determined that no random error has occurred. If the alarm threshold is greater than the verification pressure difference, it is determined that a random error has occurred in the experiment, and the regeneration threshold and alarm threshold corresponding to that interval need to be recalibrated.

[0063] To achieve accurate diagnosis of DPF overload, in one optional implementation, step S201 includes:

[0064] Step S2011: Determine the preset driving mileage range to which the current mileage belongs based on the current mileage.

[0065] Specifically, the current mileage is obtained, and the preset mileage range corresponding to the current mileage is determined.

[0066] Step S2012: Based on the preset driving mileage interval to which the current mileage belongs, query the regeneration threshold and alarm threshold corresponding to the preset driving mileage interval to which the current mileage belongs in the target mapping relationship, and obtain the target regeneration threshold and alarm threshold.

[0067] Specifically, based on the preset mileage interval corresponding to the current mileage, the second mapping relationship is queried to obtain the regeneration threshold and the alarm threshold corresponding to the threshold, that is, the target regeneration threshold and the target alarm threshold are obtained.

[0068] To eliminate the influence of exhaust gas flow rate changes on pressure differential, in an optional implementation, step S202 includes:

[0069] Step S2021: Obtain the current pressure difference, current exhaust flow rate and preset exhaust flow rate. The current pressure difference is the current filter pressure difference at the current moment, and the current exhaust flow rate is the current exhaust flow rate of the engine at the current moment.

[0070] Specifically, the ECU obtains the actual pressure difference of the DPF at the current moment, the exhaust flow rate of the engine at the current moment, and the corresponding standard exhaust flow rate, i.e. the preset exhaust flow rate, through corresponding sensors installed in different locations.

[0071] Step S2022: Calculate the product of the current pressure difference and the preset exhaust flow rate, and calculate the quotient of the product divided by the current exhaust flow rate to obtain the corrected pressure difference.

[0072] Specifically, using the preset exhaust flow rate as the standard, the current pressure difference is normalized according to the current exhaust flow rate, thereby eliminating the influence of the exhaust flow rate on the pressure difference. That is, the corrected pressure difference is calculated as: current pressure difference * preset exhaust flow rate / current exhaust flow rate.

[0073] To determine the correspondence between mileage and mileage range, in one optional implementation, after obtaining the current mileage, the method further includes:

[0074] Step S401: Obtain identification information, which includes first identification information and second identification information. The first identification information is used to indicate whether the particulate filter has been cleaned and the second identification information is used to indicate whether the particulate filter has been replaced.

[0075] Specifically, cleaning or replacing the DPF will affect the dust accumulation status of the DPF, which will cause the regeneration threshold and alarm threshold obtained from the original mileage range to not match the current dust accumulation status. Therefore, in one embodiment of this application, identification information is set to determine whether the DPF needs to be cleaned or replaced.

[0076] In practice, to ensure the accuracy of calibration data, a DPF of the same model should be used when replacing the DPF. If the replaced DPF is a different model from the original DPF, recalibration is required.

[0077] In step S402, if the second identification information indicates that the particulate filter has been replaced, the current mileage is reset to zero.

[0078] Specifically, when the DPF is replaced, there is no dust accumulation in the DPF, meaning the DPF is in its factory condition with a mileage of 0. Therefore, resetting the current mileage to zero and re-accumulating it can ensure the accuracy of overload condition diagnosis.

[0079] Step S403: When the second identification information indicates that the particulate filter has not been replaced and the first identification information indicates that the particulate filter has been cleaned, the equivalent mileage is determined based on the current pressure difference and the second curve, and the current mileage is updated to the equivalent mileage. The equivalent mileage is the driving mileage corresponding to the current pressure difference in the second curve.

[0080] Specifically, if the DPF is not replaced and is cleaned, theoretically the DPF should be restored to its factory condition. However, in actual operation, cleaning cannot completely remove the accumulated dust. Therefore, it is necessary to measure the pressure difference of the DPF after cleaning, and then calibrate it in the second curve mentioned above based on the pressure difference after cleaning to determine the equivalent mileage of the current driving distance, and start accumulating from the equivalent mileage.

[0081] In step S404, if the second identification information indicates that the particulate filter has not been replaced and the first identification information indicates that the particulate filter has not been cleaned, the current mileage remains unchanged.

[0082] Specifically, if the DPF is neither cleaned nor replaced, simply continue to accumulate mileage.

[0083] To ensure the accuracy of DPF overload diagnostic results, in one optional implementation, the method further includes the following step before obtaining the current mileage:

[0084] Step S501: Obtain the current operating condition parameters. The current operating condition parameters are the operating condition parameters at the current moment. The operating condition parameters include the engine speed, the engine torque, the engine exhaust temperature, and the signal from the differential pressure sensor.

[0085] Specifically, to ensure the accuracy of the diagnostic results, the engine needs to be in a stable operating state and the differential pressure sensors at both ends of the DPF need to be operating normally at the current moment. Therefore, the above-mentioned current operating condition parameters corresponding to the current moment need to be obtained.

[0086] Step S502: Determine whether the above current operating condition parameters meet the first condition, wherein the above first condition is that the above speed is within a first range, the above torque is within a second range, and the above exhaust temperature is within a third range.

[0087] Specifically, if the engine speed is within a preset range, the torque is within a preset range, and the engine exhaust temperature is within a certain range, it can be determined that the engine is operating stably and that no on-road regeneration is occurring in the DPF. This meets the environmental requirements for DPF overload detection.

[0088] Step S503: Determine whether the above current operating condition parameters meet the second condition. The second condition is that the above signal is within the fourth range and the rate of change of the above signal is less than the second preset value.

[0089] Specifically, if the signal from the differential pressure sensor is within the normal range and stable, it can be determined that the differential pressure sensor is not faulty and meets the device requirements for DPF overload judgment.

[0090] Step S504: If both the first condition and the second condition are met, the current mileage can be obtained.

[0091] Specifically, provided that the environmental and device requirements for DPF overload detection are met, the ECU is allowed to obtain the current mileage for overload diagnosis.

[0092] Step S505: If either the first condition or the second condition is not met, the current mileage is not allowed to be obtained.

[0093] Specifically, if either the environmental or device requirements for DPF overload detection are not met, the ECU is not allowed to obtain the current mileage for overload diagnosis.

[0094] To avoid safety hazards caused by DPF damage, in one optional implementation, after obtaining the current differential pressure, the above method further includes:

[0095] Step S601: If the current pressure difference is less than the third preset value, a second alarm message is issued. The second alarm message is used to indicate that the particulate filter has melted.

[0096] Specifically, in the case of DPF melting, the pressure difference of DPF is too low relative to the normal pressure difference. Therefore, the above-mentioned third preset value is set. When the pressure difference is lower than the third preset value, it is determined that DPF has melted and a second alarm message is issued to remind the driver to replace it as soon as possible.

[0097] To enable those skilled in the art to better understand the technical solution of this application, the implementation process of the particulate filter overload diagnosis method of this application will be described in detail below with reference to specific embodiments.

[0098] This embodiment relates to a specific method for diagnosing particulate filter overload, such as... Figure 6 As shown, it includes the following steps:

[0099] Step S1: Obtain the engine's operating conditions and the operating status of the DPF differential pressure sensor. If the engine is running stably and the DPF differential pressure sensor is operating normally, determine that the current operating conditions meet the prerequisite diagnostic conditions for DPF overload diagnosis.

[0100] Step S2: Under the condition that the pre-diagnostic conditions for DPF overload diagnosis are met under the current operating conditions, obtain the engine exhaust parameters and mileage and the measured pressure difference of DPF, determine the mileage range mentioned in the mileage, and standardize the measured pressure difference according to the exhaust parameters and the measured pressure difference to obtain the standardized pressure difference.

[0101] Step S3: Determine the corresponding full-load differential pressure threshold, overload differential pressure threshold, regeneration differential pressure threshold, and post-regeneration differential pressure threshold for each mileage interval;

[0102] Step S4: When the standardized differential pressure is greater than the full-load differential pressure threshold, the ECU disables the regeneration function and issues an alarm, prompting the driver that the current DPF is faulty or mismatched and needs to be replaced at a repair shop as soon as possible.

[0103] Step S5: When the standardized differential pressure is greater than or equal to the overload differential pressure threshold and less than the full load differential pressure threshold, the ECU disables the regeneration function and issues an alarm, prompting the driver that there is too much dust accumulation in the DPF and that the driver needs to go to the repair shop for cleaning as soon as possible.

[0104] Step S6: When the standardized differential pressure is greater than or equal to the regeneration differential pressure threshold and less than the overload differential pressure threshold, the ECU forcibly starts the regeneration function and continuously monitors the current differential pressure.

[0105] Step S7: When the standardized differential pressure is greater than or equal to the differential pressure threshold after regeneration but less than the differential pressure threshold after regeneration, the ECU allows the driver to actively perform regeneration and continuously monitors the current differential pressure.

[0106] Step S8: If the standardized differential pressure is less than the differential pressure threshold after regeneration, the ECU will disable the regeneration function and issue an alarm, indicating to the driver that the DPF has melted and needs to be replaced at a repair shop as soon as possible.

[0107] It should be noted that the steps shown in the flowchart in the accompanying drawings can be executed in a computer system such as a set of computer-executable instructions, and although a logical order is shown in the flowchart, in some cases the steps shown or described may be executed in a different order than that shown here.

[0108] This application also provides a diagnostic device for particulate filter overload. It should be noted that this diagnostic device can be used to execute the diagnostic method for particulate filter overload provided in this application. This device is used to implement the above embodiments and preferred embodiments; details already described will not be repeated. As used below, the term "module" can refer to a combination of software and / or hardware that performs a predetermined function. Although the device described in the following embodiments is preferably implemented in software, hardware implementation, or a combination of software and hardware, is also possible and contemplated.

[0109] The following describes the diagnostic device for particulate filter overload provided in the embodiments of this application.

[0110] Figure 7 This is a structural block diagram of a diagnostic device for particulate filter overload according to an embodiment of this application. Figure 7 As shown, the device includes:

[0111] The first acquisition unit 10 is used to acquire the current mileage, query the target mapping relationship based on the current mileage to obtain the target regeneration threshold and the target alarm threshold, the target regeneration threshold and the target alarm threshold are the regeneration threshold and alarm threshold corresponding to the current mileage, the current mileage is the total mileage traveled by the engine from the first moment to the current moment, the first moment is the moment when the dust cleaning ends, and the target mapping relationship is the mapping relationship between the total mileage and the regeneration threshold and the alarm threshold;

[0112] Specifically, the initial state of the DPF is as follows: Figure 3 As shown. Figure 4As shown, as engine mileage increases, ash cakes or ash plugs form in the DPF, reducing regeneration efficiency and decreasing pressure differential when the DPF is full of carbon. In one embodiment of this application, the engine mileage is divided into different driving ranges, and carbon load overload limits and carbon load regeneration limits are calibrated accordingly, thus obtaining the above-mentioned target mapping relationship. When making a judgment, the mapping relationship is queried based on the current mileage to obtain the overload pressure differential threshold and regeneration pressure differential threshold of the corresponding DPF current ash accumulation state, which are the above-mentioned target regeneration threshold and target alarm threshold.

[0113] The second acquisition unit 20 is used to acquire the corrected pressure difference, which is obtained by eliminating the pressure difference error caused by the change in exhaust gas flow rate based on the filter pressure difference monitored by the pressure sensor. The filter pressure difference is the pressure difference between the air inlet and outlet of the particulate filter.

[0114] Specifically, in order to ensure the accuracy of the diagnostic results, the actual pressure difference currently being monitored is normalized to obtain the above-mentioned corrected pressure difference, which removes the influence of different flow velocities on the pressure difference and ensures that the change in pressure difference is entirely caused by the change in carbon loading.

[0115] The first alarm unit 30 is used to control the particulate filter to regenerate when the corrected pressure difference is greater than or equal to the target regeneration threshold and less than the target alarm threshold, to control the particulate filter not to regenerate when the corrected pressure difference is less than the target regeneration threshold, and to issue a first alarm message when the corrected pressure difference is greater than or equal to the target alarm threshold. The first alarm message is used to prompt the particulate filter to be cleaned, and the target alarm threshold is greater than the target regeneration threshold.

[0116] Specifically, the corrected pressure difference is compared with the target regeneration threshold and the target alarm threshold. If the corrected pressure difference exceeds the regeneration threshold, it is determined that the carbon load meets the regeneration requirements, and the DPF is controlled to regenerate. If the corrected pressure difference exceeds the alarm threshold, it is determined that the carbon load has reached the overload limit. At this time, the ECU issues the first alarm message, prompting the driver that the DPF cannot regenerate and that they need to find the nearest service station for cleaning.

[0117] In this embodiment, the first acquisition unit acquires the current mileage, and queries the target mapping relationship based on the current mileage to obtain the target regeneration threshold and the target alarm threshold. The target regeneration threshold and the target alarm threshold are the regeneration threshold and alarm threshold corresponding to the current mileage. The current mileage is the total mileage traveled by the engine from the first moment to the current moment. The first moment is the moment when the dust removal ends. The target mapping relationship is the mapping relationship between the total mileage and the regeneration threshold and the alarm threshold. The second acquisition unit acquires the correction pressure difference, which is obtained by eliminating the exhaust gas velocity based on the filter pressure difference monitored by the pressure sensor. The pressure difference is obtained after considering the pressure difference error caused by the change. The aforementioned filtration pressure difference is the pressure difference between the air pressure at the inlet and outlet of the particulate filter. The first alarm unit controls the particulate filter to regenerate when the corrected pressure difference is greater than or equal to the target regeneration threshold and less than the target alarm threshold; it controls the particulate filter not to regenerate when the corrected pressure difference is less than the target regeneration threshold; and it issues a first alarm message when the corrected pressure difference is greater than or equal to the target alarm threshold. The first alarm message is used to remind the particulate filter that it needs cleaning. The target alarm threshold is greater than the target regeneration threshold. This application calibrates the actual pressure difference when the carbon load reaches the limit and the actual pressure difference when overloaded in different mileage segments. When making a judgment, it looks up the corresponding regeneration threshold and alarm threshold based on the mileage segment where the total mileage is located, compares the current corrected pressure difference with the threshold, and determines whether to regenerate or issue an alarm. Compared with the prior art, this application takes into account the impact of pressure difference changes when the carbon load reaches the limit or is overloaded due to dust accumulation in the particulate filter during driving on the overload judgment and the activation of the regeneration function. It solves the problem that the prior art does not consider the pressure difference changes caused by the change in the dust accumulation state of the particulate filter when limiting the overload pressure difference limit, which leads to inaccurate judgment.

[0118] In order to obtain the regeneration threshold and the alarm threshold corresponding to different driving mileage ranges, in an optional embodiment, the device further includes:

[0119] The third acquisition unit is used to perform a first acquisition step before obtaining the target regeneration threshold and the target alarm threshold by querying the target mapping relationship based on the current mileage, and to acquire a first curve, a second curve and a third curve. The first curve is the curve of overload pressure difference changing with the total mileage. The second curve is the curve of ash accumulation pressure difference changing with the total mileage. The overload pressure difference is the filtration pressure difference of the particulate filter when the carbon load in the particulate filter reaches a first preset value. The ash accumulation pressure difference is the filtration pressure difference of the particulate filter after controlling the particulate filter to regenerate. The third curve is the curve of ash accumulation in the particulate filter changing with the ash accumulation pressure difference after controlling the particulate filter to regenerate.

[0120] Specifically, such as Figure 5 As shown, curve B is the first curve mentioned above, and curve A is the second curve mentioned above. It can be seen that as the mileage increases, even when reaching full load, the pressure difference of the DPF decreases due to the membrane effect, while the pressure difference of the ash accumulation increases because the proportion of ash in the carbon load gradually increases, resulting in more ash that cannot be removed after regeneration. To explore the relationship between ash content and pressure difference, a third curve was plotted based on the second curve.

[0121] The fourth acquisition unit is used to perform the second acquisition step, the target driving mileage range, and calculate the average value of all the above-mentioned dust accumulation pressure differences in the target driving mileage range according to the above-mentioned target driving mileage range and the above-mentioned second curve to obtain the first pressure difference. The above-mentioned target driving mileage range is any one of the preset driving mileage ranges.

[0122] Specifically, to accurately determine whether the DPF is overloaded, in one embodiment of this application, the overload pressure difference and regeneration pressure difference are calibrated for different mileage intervals throughout the DPF's entire lifespan. The lifespan is expressed in terms of mileage. Any interval is then obtained to obtain the target mileage interval. Furthermore, based on the target mileage interval, a corresponding segment is extracted from the second curve, and the average value of the ash accumulation pressure difference within that interval is calculated to obtain the first pressure difference.

[0123] The first determining unit is used to perform the first determining step, determining the target ash accumulation amount based on the first pressure difference and the third curve, wherein the target ash accumulation amount is the ash accumulation amount corresponding to the first pressure difference in the third curve.

[0124] Specifically, the calibrated value is obtained by calibrating the third curve based on the first pressure difference, which is the target ash accumulation amount.

[0125] The fifth acquisition unit is used to perform the third acquisition step and acquire a fourth curve based on the target ash accumulation amount. The fourth curve is the curve of the change of the filtration pressure difference with the carbon loading when the ash accumulation amount in the particulate filter is the target ash accumulation amount.

[0126] In one embodiment of this application, the pressure difference changes with the carbon load due to the different initial ash accumulation. During the engine bench test, the relationship between the filter pressure difference and the carbon load corresponding to different initial ash accumulation is calibrated to obtain the above-mentioned fourth curve corresponding to different initial ash accumulation.

[0127] Specifically, the ECU retrieves the fourth curve stored in the ECU based on the target dust accumulation amount obtained from the calibration, thus obtaining the fourth curve corresponding to the target dust accumulation amount.

[0128] The second determining unit is used to perform the second determining step, and to determine the regeneration threshold and the alarm threshold according to the first preset carbon load, the second preset carbon load and the fourth curve. The regeneration threshold is the filter pressure difference corresponding to the first preset carbon load in the fourth curve, and the alarm threshold is the filter pressure difference corresponding to the second preset carbon load in the fourth curve. The first preset carbon load is greater than the second preset carbon load.

[0129] Specifically, after obtaining the fourth curve showing the change of filtration differential pressure with carbon load in the current interval, the fourth curve is calibrated according to the overload limit and regeneration limit of carbon load to obtain the regeneration differential pressure threshold and alarm differential pressure threshold corresponding to the threshold, that is, the above-mentioned regeneration threshold and alarm threshold are obtained.

[0130] The repeating unit is used to repeat the second acquisition step, the first determination step, the third acquisition step and the second determination step at least once in sequence until the regeneration threshold and the alarm threshold corresponding to all the preset driving mileage intervals are obtained.

[0131] Specifically, the second acquisition step, the first determination step, the third acquisition step, and the second determination step described above are repeated in sequence to determine the regeneration threshold and the alarm threshold corresponding to each of the above driving mileage intervals.

[0132] The construction unit is used to construct the target mapping relationship based on the correspondence between each of the preset driving mileage ranges, each of the regeneration thresholds and each of the alarm thresholds.

[0133] Specifically, based on the correspondence between the preset driving mileage range, the regeneration threshold, and the alarm threshold, the data is written into the corresponding positions in the table and stored in the ECU, thus obtaining the target mapping relationship.

[0134] It is important to note that, in order to ensure that the calibration results are not affected by random errors during the calibration process, after obtaining the above regeneration threshold and alarm threshold, the first curve will be calibrated according to the upper limit of the mileage in the corresponding interval to obtain the corresponding verification pressure difference. If the alarm threshold is less than the verification pressure difference, it is determined that no random error has occurred. If the alarm threshold is greater than the verification pressure difference, it is determined that a random error has occurred in the experiment, and the regeneration threshold and alarm threshold corresponding to that interval need to be recalibrated.

[0135] To achieve accurate diagnosis of DPF overload, in one optional implementation, the first acquisition unit includes:

[0136] The determination module is used to determine the preset driving mileage range to which the current mileage belongs based on the current mileage.

[0137] Specifically, the current mileage is obtained, and the preset mileage range corresponding to the current mileage is determined.

[0138] The query module queries the preset driving mileage interval to which the current mileage belongs in the target mapping relationship for the regeneration threshold and the alarm threshold corresponding to the preset driving mileage interval to which the current mileage belongs, and obtains the target regeneration threshold and the alarm threshold.

[0139] Specifically, based on the preset mileage interval corresponding to the current mileage, the second mapping relationship is queried to obtain the regeneration threshold and the alarm threshold corresponding to the threshold, that is, the target regeneration threshold and the target alarm threshold are obtained.

[0140] To eliminate the influence of exhaust gas flow rate changes on pressure differential, in one optional implementation, the second acquisition unit includes:

[0141] The acquisition module is used to acquire the current pressure difference, the current exhaust flow rate, and the preset exhaust flow rate. The current pressure difference is the current filter pressure difference at the current moment, and the current exhaust flow rate is the current exhaust flow rate of the engine at the current moment.

[0142] Specifically, the ECU obtains the actual pressure difference of the DPF at the current moment, the exhaust flow rate of the engine at the current moment, and the corresponding standard exhaust flow rate, i.e. the preset exhaust flow rate, through corresponding sensors installed in different locations.

[0143] The calculation module is used to calculate the product of the current pressure difference and the preset exhaust flow rate, and to calculate the quotient of the product divided by the current exhaust flow rate to obtain the corrected pressure difference.

[0144] Specifically, using the preset exhaust flow rate as the standard, the current pressure difference is normalized according to the current exhaust flow rate, thereby eliminating the influence of the exhaust flow rate on the pressure difference. That is, the corrected pressure difference is calculated as: current pressure difference * preset exhaust flow rate / current exhaust flow rate.

[0145] To determine the correspondence between mileage and mileage range, in one optional embodiment, the above-mentioned device further includes:

[0146] The sixth acquisition unit is used to acquire identification information after acquiring the current mileage. The identification information includes first identification information and second identification information. The first identification information is used to indicate whether the particulate filter has been cleaned and the second identification information is used to indicate whether the particulate filter has been replaced.

[0147] Specifically, cleaning or replacing the DPF will affect the dust accumulation status of the DPF, which will cause the regeneration threshold and alarm threshold obtained from the original mileage range to not match the current dust accumulation status. Therefore, in one embodiment of this application, identification information is set to determine whether the DPF needs to be cleaned or replaced.

[0148] In practice, to ensure the accuracy of calibration data, a DPF of the same model should be used when replacing the DPF. If the replaced DPF is a different model from the original DPF, recalibration is required.

[0149] The first update unit is used to reset the current mileage to zero when the second identification information indicates that the particulate filter has been replaced.

[0150] Specifically, when the DPF is replaced, there is no dust accumulation in the DPF, meaning the DPF is in its factory condition with a mileage of 0. Therefore, resetting the current mileage to zero and re-accumulating it can ensure the accuracy of overload condition diagnosis.

[0151] The second updating unit is used to determine the equivalent mileage based on the current pressure difference and the second curve and update the current mileage to the equivalent mileage when the second identification information indicates that the particulate filter has not been replaced and the first identification information indicates that the particulate filter has been cleaned. The equivalent mileage is the driving mileage corresponding to the current pressure difference in the second curve.

[0152] Specifically, if the DPF is not replaced and is cleaned, theoretically the DPF should be restored to its factory condition. However, in actual operation, cleaning cannot completely remove the accumulated dust. Therefore, it is necessary to measure the pressure difference of the DPF after cleaning, and then calibrate it in the second curve mentioned above based on the pressure difference after cleaning to determine the equivalent mileage of the current driving distance, and start accumulating from the equivalent mileage.

[0153] The third update unit is used to keep the current mileage unchanged when the second identification information indicates that the particulate filter has not been replaced and the first identification information indicates that the particulate filter has not been cleaned.

[0154] Specifically, if the DPF is neither cleaned nor replaced, simply continue to accumulate mileage.

[0155] To ensure the accuracy of DPF overload diagnostic results, in one optional embodiment, the above-mentioned device further includes:

[0156] The seventh acquisition unit is used to acquire current operating condition parameters before acquiring the current mileage. The current operating condition parameters are the operating condition parameters at the current moment. The operating condition parameters include the engine speed, the engine torque, the engine exhaust temperature, and the signal from the differential pressure sensor.

[0157] Specifically, to ensure the accuracy of the diagnostic results, the engine needs to be in a stable operating state and the differential pressure sensors at both ends of the DPF need to be operating normally at the current moment. Therefore, the above-mentioned current operating condition parameters corresponding to the current moment need to be obtained.

[0158] The third determining unit is used to determine whether the above-mentioned current operating condition parameters meet the first condition, wherein the above-mentioned first condition is that the above-mentioned speed is within a first range, the above-mentioned torque is within a second range, and the above-mentioned exhaust temperature is within a third range.

[0159] Specifically, if the engine speed is within a preset range, the torque is within a preset range, and the engine exhaust temperature is within a certain range, it can be determined that the engine is operating stably and that no on-road regeneration is occurring in the DPF. This meets the environmental requirements for DPF overload detection.

[0160] The fourth determining unit is used to determine whether the above-mentioned current operating condition parameters meet the second condition, wherein the second condition is that the above-mentioned signal is within the fourth range and the rate of change of the above-mentioned signal is less than the second preset value;

[0161] Specifically, if the signal from the differential pressure sensor is within the normal range and stable, it can be determined that the differential pressure sensor is not faulty and meets the device requirements for DPF overload judgment.

[0162] A first control unit is configured to allow the acquisition of the current mileage when both the first condition and the second condition are met.

[0163] Specifically, provided that the environmental and device requirements for DPF overload detection are met, the ECU is allowed to obtain the current mileage for overload diagnosis.

[0164] The second control unit is configured to disallow the acquisition of the current mileage if either the first condition or the second condition is not met.

[0165] Specifically, if either the environmental or device requirements for DPF overload detection are not met, the ECU is not allowed to obtain the current mileage for overload diagnosis.

[0166] To avoid safety hazards caused by DPF damage, in one optional embodiment, the above-mentioned device further includes:

[0167] The second alarm unit is used to issue a second alarm message when the current pressure difference is less than a third preset value after the current pressure difference is obtained. The second alarm message is used to indicate that the particulate filter has melted.

[0168] The aforementioned particulate filter overload diagnostic device includes a processor and a memory. The first acquisition unit, the second acquisition unit, and the first alarm unit are all stored as program units in the memory. The processor executes these program units stored in the memory to achieve their respective functions. All of the above modules reside in the same processor; alternatively, the modules may be located in different processors in any combination.

[0169] The processor contains a kernel, which retrieves the corresponding program unit from memory. One or more kernels can be configured, and adjusting kernel parameters can improve the accuracy of DPF overload diagnostics.

[0170] The memory may include non-permanent memory in computer-readable media, such as random access memory (RAM) and / or non-volatile memory, such as read-only memory (ROM) or flash RAM, and the memory includes at least one memory chip.

[0171] This invention provides a computer-readable storage medium including a stored program, wherein, when the program is executed, it controls the device containing the computer-readable storage medium to perform the particulate filter overload diagnostic method.

[0172] Specifically, diagnostic methods for particulate filter overload include:

[0173] Step S201: Obtain the current mileage, and query the target mapping relationship based on the current mileage to obtain the target regeneration threshold and the target alarm threshold. The target regeneration threshold and the target alarm threshold are the regeneration threshold and alarm threshold corresponding to the current mileage. The current mileage is the total mileage traveled by the engine from the first moment to the current moment. The first moment is the moment when the dust cleaning ends. The target mapping relationship is the mapping relationship between the total mileage and the regeneration threshold and the alarm threshold.

[0174] Specifically, the initial state of the DPF is as follows: Figure 3 As shown. Figure 4As shown, as engine mileage increases, ash cakes or ash plugs form in the DPF, reducing regeneration efficiency and decreasing pressure differential when the DPF is full of carbon. In one embodiment of this application, the engine mileage is divided into different driving ranges, and carbon load overload limits and carbon load regeneration limits are calibrated accordingly, thus obtaining the above-mentioned target mapping relationship. When making a judgment, the mapping relationship is queried based on the current mileage to obtain the overload pressure differential threshold and regeneration pressure differential threshold of the corresponding DPF current ash accumulation state, which are the above-mentioned target regeneration threshold and target alarm threshold.

[0175] Step S202: Obtain the corrected pressure difference. The corrected pressure difference is obtained by eliminating the pressure difference error caused by the change in exhaust gas flow rate based on the filter pressure difference monitored by the pressure sensor. The filter pressure difference is the pressure difference between the air inlet and outlet of the particulate filter.

[0176] Specifically, in order to ensure the accuracy of the diagnostic results, the actual pressure difference currently being monitored is normalized to obtain the above-mentioned corrected pressure difference, which removes the influence of different flow velocities on the pressure difference and ensures that the change in pressure difference is entirely caused by the change in carbon loading.

[0177] Step S203: When the corrected pressure difference is greater than or equal to the target regeneration threshold and less than the target alarm threshold, control the particulate filter to regenerate; when the corrected pressure difference is less than the target regeneration threshold, control the particulate filter not to regenerate; when the corrected pressure difference is greater than or equal to the target alarm threshold, issue a first alarm message. The first alarm message is used to prompt the particulate filter to be cleaned. The target alarm threshold is greater than the target regeneration threshold.

[0178] Specifically, the corrected pressure difference is compared with the target regeneration threshold and the target alarm threshold. If the corrected pressure difference exceeds the regeneration threshold, it is determined that the carbon load meets the regeneration requirements, and the DPF is controlled to regenerate. If the corrected pressure difference exceeds the alarm threshold, it is determined that the carbon load has reached the overload limit. At this time, the ECU issues the first alarm message, prompting the driver that the DPF cannot regenerate and that they need to find the nearest service station for cleaning.

[0179] This invention provides a processor for running a program, wherein the program executes the particulate filter overload diagnostic method.

[0180] Specifically, diagnostic methods for particulate filter overload include:

[0181] Step S201: Obtain the current mileage, and query the target mapping relationship based on the current mileage to obtain the target regeneration threshold and the target alarm threshold. The target regeneration threshold and the target alarm threshold are the regeneration threshold and alarm threshold corresponding to the current mileage. The current mileage is the total mileage traveled by the engine from the first moment to the current moment. The first moment is the moment when the dust cleaning ends. The target mapping relationship is the mapping relationship between the total mileage and the regeneration threshold and the alarm threshold.

[0182] Specifically, the initial state of the DPF is as follows: Figure 3 As shown. Figure 4 As shown, as engine mileage increases, ash cakes or ash plugs form in the DPF, reducing regeneration efficiency and decreasing pressure differential when the DPF is full of carbon. In one embodiment of this application, the engine mileage is divided into different driving ranges, and carbon load overload limits and carbon load regeneration limits are calibrated accordingly, thus obtaining the above-mentioned target mapping relationship. When making a judgment, the mapping relationship is queried based on the current mileage to obtain the overload pressure differential threshold and regeneration pressure differential threshold of the corresponding DPF current ash accumulation state, which are the above-mentioned target regeneration threshold and target alarm threshold.

[0183] Step S202: Obtain the corrected pressure difference. The corrected pressure difference is obtained by eliminating the pressure difference error caused by the change in exhaust gas flow rate based on the filter pressure difference monitored by the pressure sensor. The filter pressure difference is the pressure difference between the air inlet and outlet of the particulate filter.

[0184] Specifically, in order to ensure the accuracy of the diagnostic results, the actual pressure difference currently being monitored is normalized to obtain the above-mentioned corrected pressure difference, which removes the influence of different flow velocities on the pressure difference and ensures that the change in pressure difference is entirely caused by the change in carbon loading.

[0185] Step S203: When the corrected pressure difference is greater than or equal to the target regeneration threshold and less than the target alarm threshold, control the particulate filter to regenerate; when the corrected pressure difference is less than the target regeneration threshold, control the particulate filter not to regenerate; when the corrected pressure difference is greater than or equal to the target alarm threshold, issue a first alarm message. The first alarm message is used to prompt the particulate filter to be cleaned. The target alarm threshold is greater than the target regeneration threshold.

[0186] Specifically, the corrected pressure difference is compared with the target regeneration threshold and the target alarm threshold. If the corrected pressure difference exceeds the regeneration threshold, it is determined that the carbon load meets the regeneration requirements, and the DPF is controlled to regenerate. If the corrected pressure difference exceeds the alarm threshold, it is determined that the carbon load has reached the overload limit. At this time, the ECU issues the first alarm message, prompting the driver that the DPF cannot regenerate and that they need to find the nearest service station for cleaning.

[0187] This invention provides a vehicle, which includes a processor, a memory, and a program stored in the memory and executable on the processor. When the processor executes the program, it performs at least the following steps:

[0188] Step S201: Obtain the current mileage, and query the target mapping relationship based on the current mileage to obtain the target regeneration threshold and the target alarm threshold. The target regeneration threshold and the target alarm threshold are the regeneration threshold and alarm threshold corresponding to the current mileage. The current mileage is the total mileage traveled by the engine from the first moment to the current moment. The first moment is the moment when the dust cleaning ends. The target mapping relationship is the mapping relationship between the total mileage and the regeneration threshold and the alarm threshold.

[0189] Step S202: Obtain the corrected pressure difference. The corrected pressure difference is obtained by eliminating the pressure difference error caused by the change in exhaust gas flow rate based on the filter pressure difference monitored by the pressure sensor. The filter pressure difference is the pressure difference between the air inlet and outlet of the particulate filter.

[0190] Step S203: When the corrected pressure difference is greater than or equal to the target regeneration threshold and less than the target alarm threshold, control the particulate filter to regenerate; when the corrected pressure difference is less than the target regeneration threshold, control the particulate filter not to regenerate; when the corrected pressure difference is greater than or equal to the target alarm threshold, issue a first alarm message. The first alarm message is used to prompt the particulate filter to be cleaned. The target alarm threshold is greater than the target regeneration threshold.

[0191] This application also provides a computer program product, which, when executed on a data processing device, is suitable for executing an initialization program having at least the following method steps:

[0192] Step S201: Obtain the current mileage, and query the target mapping relationship based on the current mileage to obtain the target regeneration threshold and the target alarm threshold. The target regeneration threshold and the target alarm threshold are the regeneration threshold and alarm threshold corresponding to the current mileage. The current mileage is the total mileage traveled by the engine from the first moment to the current moment. The first moment is the moment when the dust cleaning ends. The target mapping relationship is the mapping relationship between the total mileage and the regeneration threshold and the alarm threshold.

[0193] Step S202: Obtain the corrected pressure difference. The corrected pressure difference is obtained by eliminating the pressure difference error caused by the change in exhaust gas flow rate based on the filter pressure difference monitored by the pressure sensor. The filter pressure difference is the pressure difference between the air inlet and outlet of the particulate filter.

[0194] Step S203: When the corrected pressure difference is greater than or equal to the target regeneration threshold and less than the target alarm threshold, control the particulate filter to regenerate; when the corrected pressure difference is less than the target regeneration threshold, control the particulate filter not to regenerate; when the corrected pressure difference is greater than or equal to the target alarm threshold, issue a first alarm message. The first alarm message is used to prompt the particulate filter to be cleaned. The target alarm threshold is greater than the target regeneration threshold.

[0195] It is obvious to those skilled in the art that the modules or steps of the present invention described above can be implemented using general-purpose computing devices. They can be centralized on a single computing device or distributed across a network of multiple computing devices. They can be implemented using computer-executable program code, and thus can be stored in a storage device for execution by a computing device. In some cases, the steps shown or described can be performed in a different order than those described herein, or they can be fabricated as separate integrated circuit modules, or multiple modules or steps can be fabricated as a single integrated circuit module. Thus, the present invention is not limited to any particular combination of hardware and software.

[0196] Those skilled in the art will understand that embodiments of this application can be provided as methods, systems, or computer program products. Therefore, this application can take the form of a completely hardware embodiment, a completely software embodiment, or an embodiment combining software and hardware aspects. Furthermore, this application can take the form of a computer program product embodied on one or more computer-usable storage media (including but not limited to disk storage, CD-ROM, optical storage, etc.) containing computer-usable program code.

[0197] This application is described with reference to flowchart illustrations and / or block diagrams of methods, apparatus (systems), and computer program products according to embodiments of this application. It will be understood that each block of the flowchart illustrations and / or block diagrams, and combinations of blocks in the flowchart illustrations and / or block diagrams, can be implemented by computer program instructions. These computer program instructions can be provided to a processor of a general-purpose computer, special-purpose computer, embedded processor, or other programmable data processing apparatus to produce a machine, such that the instructions, which execute via the processor of the computer or other programmable data processing apparatus, generate instructions for implementing the flowchart... Figure 1 One or more processes and / or boxes Figure 1 A device that provides the functions specified in one or more boxes.

[0198] These computer program instructions may also be stored in a computer-readable storage medium that can direct a computer or other programmable data processing device to function in a particular manner, such that the instructions stored in the computer-readable storage medium produce an article of manufacture including instruction means, which are implemented in a process Figure 1 One or more processes and / or boxes Figure 1 The function specified in one or more boxes.

[0199] These computer program instructions may also be loaded onto a computer or other programmable data processing equipment to cause a series of operational steps to be performed on the computer or other programmable equipment to produce a computer-implemented process, thereby providing instructions that execute on the computer or other programmable equipment for implementing the process. Figure 1 One or more processes and / or boxes Figure 1 The steps of the function specified in one or more boxes.

[0200] In a typical configuration, a computing device includes one or more processors (CPU), input / output interfaces, network interfaces, and memory.

[0201] Memory may include non-persistent memory in computer-readable media, such as random access memory (RAM) and / or non-volatile memory, such as read-only memory (ROM) or flash RAM. Memory is an example of computer-readable media.

[0202] Computer-readable media includes both permanent and non-permanent, removable and non-removable media that can store information using any method or technology. Information can be computer-readable instructions, data structures, modules of programs, or other data. Examples of computer storage media include, but are not limited to, phase-change memory (PRAM), static random access memory (SRAM), dynamic random access memory (DRAM), other types of random access memory (RAM), read-only memory (ROM), electrically erasable programmable read-only memory (EEPROM), flash memory or other memory technologies, CD-ROM, digital versatile optical disc (DVD) or other optical storage, magnetic tape, magnetic magnetic disk storage or other magnetic storage devices, or any other non-transferable medium that can be used to store information accessible by a computing device. As defined herein, computer-readable media does not include transient computer-readable media, such as modulated data signals and carrier waves.

[0203] It should also be noted that the terms "comprising," "including," or any other variations thereof are intended to cover non-exclusive inclusion, such that a process, method, article, or apparatus that comprises a list of elements includes not only those elements but also other elements not expressly listed, or elements inherent to such process, method, article, or apparatus. Unless otherwise specified, an element defined by the phrase "comprising one..." does not exclude the presence of other identical elements in the process, method, article, or apparatus that includes that element.

[0204] As can be seen from the above description, the embodiments of this application achieve the following technical effects:

[0205] 1) The particulate filter overload diagnosis method of this application firstly obtains the current mileage, and then queries the target mapping relationship based on the current mileage to obtain the target regeneration threshold and the target alarm threshold. The target regeneration threshold and the target alarm threshold are the regeneration threshold and alarm threshold corresponding to the current mileage. The current mileage is the total mileage traveled by the engine from the first moment to the current moment. The first moment is the moment when the dust cleaning ends. The target mapping relationship is the mapping relationship between the total mileage and the regeneration threshold and the alarm threshold. Then, the corrected pressure difference is obtained. The corrected pressure difference is obtained based on the filter pressure difference monitored by the pressure sensor. After accounting for the pressure difference error caused by changes in exhaust gas velocity, the aforementioned filtration pressure difference is the pressure difference between the air pressure at the inlet and outlet of the particulate filter. Finally, if the corrected pressure difference is greater than or equal to the target regeneration threshold and less than the target alarm threshold, the particulate filter is controlled to regenerate. If the corrected pressure difference is less than the target regeneration threshold, the particulate filter is controlled not to regenerate. If the corrected pressure difference is greater than or equal to the target alarm threshold, a first alarm message is issued. This first alarm message is used to indicate that the particulate filter needs cleaning. The target alarm threshold is greater than the target regeneration threshold. This application calibrates the actual pressure difference when the carbon load reaches the limit and the actual pressure difference when overloaded in different mileage segments. When making a judgment, based on the mileage segment where the total mileage is located, the corresponding regeneration threshold and alarm threshold are consulted. The corrected pressure difference at the current moment is compared with the threshold to determine whether to regenerate or issue an alarm. Compared with the prior art, this application takes into account the impact of pressure difference changes when the carbon load reaches the limit or is overloaded due to dust accumulation in the particulate filter during driving on the overload judgment and the activation of the regeneration function. It solves the problem that the prior art does not consider the pressure difference changes caused by the change in the dust accumulation state of the particulate filter when limiting the overload pressure difference limit, which leads to inaccurate judgment.

[0206] 2) The particulate filter overload diagnostic device of this application comprises: a first acquisition unit acquiring the current mileage, querying a target mapping relationship based on the current mileage to obtain a target regeneration threshold and a target alarm threshold, wherein the target regeneration threshold and the target alarm threshold are the regeneration threshold and alarm threshold corresponding to the current mileage, the current mileage being the total mileage traveled by the engine from a first moment to the current moment, the first moment being the moment when the dust removal ends, and the target mapping relationship being the mapping relationship between the total mileage and the regeneration threshold and the alarm threshold; and a second acquisition unit acquiring a correction pressure difference, wherein the correction pressure difference is the filtration pressure difference monitored by a pressure sensor. After eliminating the pressure difference error caused by changes in exhaust gas velocity, the aforementioned filtration pressure difference is the pressure difference between the air pressure at the inlet and outlet of the particulate filter. The first alarm unit controls the particulate filter to regenerate when the corrected pressure difference is greater than or equal to the target regeneration threshold and less than the target alarm threshold; it controls the particulate filter not to regenerate when the corrected pressure difference is less than the target regeneration threshold; and it issues a first alarm message when the corrected pressure difference is greater than or equal to the target alarm threshold. The first alarm message is used to remind the particulate filter that it needs cleaning. The target alarm threshold is greater than the target regeneration threshold. This application calibrates the actual pressure difference when the carbon load reaches the limit and the actual pressure difference when overloaded in different mileage segments. When making a judgment, it looks up the corresponding regeneration threshold and alarm threshold based on the mileage segment where the total mileage is located, compares the current corrected pressure difference with the threshold, and determines whether to regenerate or issue an alarm. Compared with the prior art, this application takes into account the impact of pressure difference changes when the carbon load reaches the limit or is overloaded due to dust accumulation in the particulate filter during driving on the overload judgment and the activation of the regeneration function. It solves the problem that the prior art does not consider the pressure difference changes caused by the change in the dust accumulation state of the particulate filter when limiting the overload pressure difference limit, which leads to inaccurate judgment.

[0207] The above description is merely a preferred embodiment of this application and is not intended to limit this application. Various modifications and variations can be made to this application by those skilled in the art. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of this application should be included within the protection scope of this application.

Claims

1. A method of diagnosing a particulate filter overload, characterized by, The engine's exhaust port is connected to the intake port of the particulate filter, the particulate filter being used to treat the engine's exhaust gas, the method comprising: Obtain the current mileage, and query the target mapping relationship based on the current mileage to obtain the target regeneration threshold and the target alarm threshold. The target regeneration threshold and the target alarm threshold are the regeneration threshold and alarm threshold corresponding to the current mileage. The current mileage is the total mileage traveled by the engine from the first moment to the current moment. The first moment is the moment when the dust cleaning ends. The target mapping relationship is the mapping relationship between the total mileage and the regeneration threshold and the alarm threshold. Obtain the corrected differential pressure, which is obtained by eliminating the differential pressure error caused by the change in exhaust gas velocity based on the filter differential pressure monitored by the pressure sensor. The filter differential pressure is the pressure difference between the air pressure at the air inlet and the air outlet of the particulate filter. When the corrected pressure difference is greater than or equal to the target regeneration threshold and less than the target alarm threshold, the particulate filter is controlled to regenerate. When the corrected pressure difference is less than the target regeneration threshold, the particulate filter is controlled not to regenerate. When the corrected pressure difference is greater than or equal to the target alarm threshold, a first alarm message is issued. The first alarm message is used to prompt the particulate filter to be cleaned. The target alarm threshold is greater than the target regeneration threshold. To obtain the corrected differential pressure, the following steps are required: The current pressure difference, current exhaust flow rate, and preset exhaust flow rate are obtained, wherein the current pressure difference is the filter pressure difference at the current moment, and the current exhaust flow rate is the exhaust flow rate of the engine at the current moment; Calculate the product of the current pressure difference and the preset exhaust flow rate, and then calculate the quotient of the product divided by the current exhaust flow rate to obtain the corrected pressure difference.

2. The method of claim 1, wherein, Before obtaining the target regeneration threshold and target alarm threshold by querying the target mapping relationship based on the current mileage, the method further includes: The first acquisition step involves acquiring a first curve, a second curve, and a third curve. The first curve is the curve showing the change of overload pressure difference with the total mileage. The second curve is the curve showing the change of ash accumulation pressure difference with the total mileage. The overload pressure difference is the filtration pressure difference of the particulate filter when the carbon load in the particulate filter reaches a first preset value. The ash accumulation pressure difference is the filtration pressure difference of the particulate filter after regeneration. The third curve is the curve showing the change of ash accumulation in the particulate filter with the ash accumulation pressure difference after regeneration. The second acquisition step is to obtain the first pressure difference by calculating the average value of all the ash pressure differences within the target driving range based on the target driving range and the second curve. The target driving range is any one of the preset driving ranges. The first determining step is to determine the target ash accumulation amount based on the first pressure difference and the third curve, wherein the target ash accumulation amount is the ash accumulation amount corresponding to the first pressure difference in the third curve; The third step is to obtain a fourth curve based on the target ash accumulation amount. The fourth curve is the curve of the filtration pressure difference changing with the carbon loading when the ash accumulation amount in the particulate filter is the target ash accumulation amount. The second determining step involves determining a regeneration threshold and an alarm threshold based on the first preset carbon load, the second preset carbon load, and the fourth curve. The regeneration threshold is the filtration pressure difference corresponding to the first preset carbon load in the fourth curve, and the alarm threshold is the filtration pressure difference corresponding to the second preset carbon load in the fourth curve. The first preset carbon load is greater than the second preset carbon load. The second acquisition step, the first determination step, the third acquisition step, and the second determination step are repeated at least once in sequence until the regeneration threshold and the alarm threshold corresponding to all the preset driving mileage intervals are obtained. The target mapping relationship is constructed based on the correspondence between each preset driving mileage range, each regeneration threshold, and each alarm threshold.

3. The method of claim 2, wherein, Based on the current mileage, the target regeneration threshold and target alarm threshold are obtained by querying the target mapping relationship, including: The preset driving mileage range to which the current mileage belongs is determined based on the current mileage; Based on the preset mileage interval to which the current mileage belongs, query the regeneration threshold and the alarm threshold corresponding to the preset mileage interval to which the current mileage belongs in the target mapping relationship to obtain the target regeneration threshold and the target alarm threshold.

4. The method of claim 2, wherein, After obtaining the current mileage, the method further includes: Obtain identification information, which includes first identification information and second identification information. The first identification information is used to indicate whether the particulate filter needs to be cleaned, and the second identification information is used to indicate whether the particulate filter needs to be replaced. If the second identification information indicates that the particulate filter has been replaced, the current mileage is reset to zero; When the second identification information indicates that the particulate filter has not been replaced and the first identification information indicates that the particulate filter has been cleaned, the equivalent mileage is determined based on the current pressure difference and the second curve, and the current mileage is updated to the equivalent mileage, where the equivalent mileage is the driving mileage corresponding to the current pressure difference in the second curve; If the second identification information indicates that the particulate filter has not been replaced and the first identification information indicates that the particulate filter has not been cleaned, the current mileage remains unchanged.

5. The method of claim 1, wherein, Before obtaining the current mileage, the method further includes: Obtain current operating condition parameters, which are the operating condition parameters at the current moment, including the engine speed, the engine torque, the engine exhaust temperature, and the signal from the differential pressure sensor; Determine whether the current operating condition parameters meet a first condition, wherein the first condition is that the rotational speed is within a first range, the torque is within a second range, and the exhaust temperature is within a third range; Determine whether the current operating condition parameters meet the second condition, wherein the second condition is that the signal is within the fourth range and the rate of change of the signal is less than the second preset value; The current mileage is allowed to be obtained if both the first and second conditions are met. If either the first condition or the second condition is not met, the current mileage cannot be obtained.

6. The method of claim 1, wherein, After obtaining the current differential pressure, the method further includes: If the current pressure difference is less than a third preset value, a second alarm message is issued, which is used to indicate that the particulate filter has melted.

7. A diagnostic device for diagnosing overload of a particulate filter, characterized by The engine's exhaust port is connected to the particulate filter's intake port. The particulate filter is used to treat the engine's exhaust gas. The device includes: The first acquisition unit is used to acquire the current mileage, query the target mapping relationship based on the current mileage to obtain the target regeneration threshold and the target alarm threshold, wherein the target regeneration threshold and the target alarm threshold are the regeneration threshold and alarm threshold corresponding to the current mileage, the current mileage is the total mileage traveled by the engine from the first moment to the current moment, the first moment is the moment when the dust cleaning ends, and the target mapping relationship is the mapping relationship between the total mileage and the regeneration threshold and the alarm threshold; The second acquisition unit is used to acquire the corrected pressure difference, which is obtained by eliminating the pressure difference error caused by the change in exhaust gas velocity based on the filter pressure difference monitored by the pressure sensor. The filter pressure difference is the pressure difference between the air inlet and the air outlet of the particulate filter. The first alarm unit is used to control the particulate filter to regenerate when the corrected pressure difference is greater than or equal to the target regeneration threshold and less than the target alarm threshold, control the particulate filter not to regenerate when the corrected pressure difference is less than the target regeneration threshold, and issue a first alarm message when the corrected pressure difference is greater than or equal to the target alarm threshold. The first alarm message is used to prompt the particulate filter to be cleaned, and the target alarm threshold is greater than the target regeneration threshold. The second acquisition unit includes: The acquisition module is used to acquire the current pressure difference, the current exhaust flow rate, and the preset exhaust flow rate, wherein the current pressure difference is the filter pressure difference at the current moment, and the current exhaust flow rate is the exhaust flow rate of the engine at the current moment; The calculation module is used to calculate the product of the current pressure difference and the preset exhaust flow rate, and to calculate the quotient of the product divided by the current exhaust flow rate to obtain the corrected pressure difference.

8. A computer-readable storage medium, characterized in that, The computer-readable storage medium includes a stored program, wherein, when the program is executed, it controls the device on which the computer-readable storage medium is located to perform the method according to any one of claims 1 to 6.

9. A vehicle, characterized in that, include: One or more processors, a memory, and one or more programs, wherein the one or more programs are stored in the memory and configured to be executed by the one or more processors, the one or more programs comprising methods for performing any one of claims 1 to 6.

Images