A DPF removal diagnostic system, method, diesel engine, and vehicle

Abstract

This disclosure relates to a DPF removal diagnostic system, method, diesel engine, and vehicle. The method includes: determining whether the current upstream temperature value of the DPF is between a preset upper threshold temperature and a preset lower threshold temperature, and whether the gradient of the current upstream temperature value of the DPF is continuously positive or negative and exceeds a preset first time threshold; if satisfied, starting to accumulate diesel engine power and diesel engine running time, and simultaneously calculating the DPF temperature difference rate per unit time with each time step as the unit time; when the upstream temperature gradient of the DPF rises or falls to 0, the DPF temperature difference rate calculation ends; determining whether the accumulated engine power in the current interval is greater than a preset power threshold or the engine running time is greater than a second time threshold, if so, calculating the maximum value of the DPF temperature difference rate per unit time in the current interval, and if the maximum value of the DPF temperature difference rate per unit time is less than a preset temperature difference rate threshold, then reporting a fault.

Description

Technical Field

[0001] This disclosure relates to the field of engine control technology, and more specifically, to a DPF removal diagnostic system, method, diesel engine, and vehicle. Background Technology

[0002] In diesel engine aftertreatment systems, Diesel Particulate Filters (DPFs) are used to reduce particulate emissions. Currently, heavy-duty diesel vehicles typically employ a monitoring strategy based on DPF differential pressure sensors, comparing measurements from sensors across the vehicle with differential pressure limits. However, deviations in differential pressure measurements, and even false alarms of DPF removal, can occur due to factors such as aftertreatment system layout, differential pressure piping arrangement, and leaks, reducing the stability of the monitoring strategy. Therefore, improving the stability of DPF removal diagnostics and reducing false alarms by monitoring temperature changes upstream and downstream of the DPF is a pressing issue that needs to be addressed. Summary of the Invention

[0003] The main objective of this invention is to solve the technical problem of improving the stability of DPF removal diagnosis and reducing the false alarm rate by monitoring the temperature change patterns upstream and downstream of the DPF.

[0004] To achieve the above technical objectives, this disclosure provides a DPF removal diagnostic method, the method comprising:

[0005] Obtain the current upstream temperature value and the current downstream temperature value of the DPF;

[0006] Determine whether the current upstream temperature value of the DPF is between a preset upper threshold temperature and a preset lower threshold temperature, and whether the gradient of the current upstream temperature value of the DPF is continuously positive or negative and exceeds a preset first time threshold.

[0007] If the conditions are met, the diesel engine power and diesel engine running time will be accumulated, and the DPF temperature difference rate will be calculated for each unit of time with each time step as the unit of time.

[0008] When the upstream temperature gradient of the DPF reaches 0, that is, when the continuous decrease or increase in temperature ends, the calculation of the DPF temperature difference rate ends.

[0009] Determine whether the cumulative engine power in the current interval is greater than the preset power threshold or the engine running time is greater than the second time threshold. If so, calculate the maximum value of the DPF temperature difference rate in each unit time in the current interval. If the maximum value of the DPF temperature difference rate in each unit time in the current interval is less than the preset temperature difference rate threshold, report a fault.

[0010] If the conditions are not met, the process continues to return to determining whether the current upstream temperature value of the DPF is between the preset upper threshold temperature and the preset lower threshold temperature, and whether the gradient of the current upstream temperature value of the DPF is continuously positive or negative and exceeds the preset first time threshold.

[0011] Furthermore, the calculation of the DPF temperature difference rate per unit time, with each time step as the unit of time, is specifically calculated according to the following formula: ρ = DPF temperature difference rate per unit time.

[0012] ρ = (DPF upstream temperature - DPF downstream temperature) / DPF downstream temperature.

[0013] Furthermore, if the condition exists, the maximum value of the DPF temperature difference rate per unit time within the current interval is calculated. If the maximum value of the DPF temperature difference rate per unit time within the current interval is greater than or equal to a preset temperature difference rate threshold, the method further includes:

[0014] If the determination result of whether the current upstream temperature value of the DPF is between the preset upper threshold temperature and the preset lower threshold temperature, and whether the gradient of the current upstream temperature value of the DPF is continuously positive or negative and exceeds the preset first time threshold, and whether the time exceeds the third time threshold or the vehicle mileage is greater than the preset distance threshold, then the regeneration mode is entered to increase the DPF temperature until the upstream temperature of the DPF increases to a temperature greater than the preset temperature threshold and continues to exceed the preset fourth time threshold for a period of time. Then the regeneration mode is exited and the process of determining whether the current upstream temperature value of the DPF is between the preset upper threshold temperature and the preset lower threshold temperature, and whether the gradient of the current upstream temperature value of the DPF is continuously positive or negative and exceeds the preset first time threshold is returned.

[0015] The temperature rise of the upstream DPF is the difference between the upstream DPF temperature and the upstream DPF temperature before regeneration.

[0016] Furthermore, when determining whether the current upstream temperature value of the DPF is between a preset upper threshold temperature and a preset lower threshold temperature, and whether the gradient of the current upstream temperature value of the DPF is continuously positive or negative and exceeds a preset first time threshold, if the determination result is yes, and the time exceeds a third time threshold, or if the determination result is no, and the vehicle's mileage is greater than a preset distance threshold, the process returns to determining whether the current upstream temperature value of the DPF is between a preset upper threshold temperature and a preset lower threshold temperature, and whether the gradient of the current upstream temperature value of the DPF is continuously positive or negative and exceeds a preset first time threshold.

[0017] To achieve the above-mentioned technical objectives, this disclosure also provides a DPF removal diagnostic system, the system comprising:

[0018] The temperature acquisition module is used to obtain the current upstream temperature value and the current downstream temperature value of the DPF.

[0019] The first judgment module is used to determine whether the current upstream temperature value of the DPF is between a preset upper threshold temperature and a preset lower threshold temperature and whether the gradient of the current upstream temperature value of the DPF is continuously positive or negative and exceeds a preset first time threshold.

[0020] The second judgment module is used to determine whether the cumulative engine power in the current interval is greater than a preset power threshold or the engine running time is greater than a second time threshold. If so, the maximum value of the DPF temperature difference rate in each unit time in the current interval is calculated. If the maximum value of the DPF temperature difference rate in each unit time in the current interval is less than the preset temperature difference rate threshold, a fault is reported.

[0021] Furthermore, the calculation of the DPF temperature difference rate per unit time, with each time step as the unit of time, is specifically calculated according to the following formula: ρ = DPF temperature difference rate per unit time.

[0022] ρ = (DPF upstream temperature - DPF downstream temperature) / DPF downstream temperature.

[0023] Furthermore, the system also includes:

[0024] The third judgment module is used to determine whether the current upstream temperature value of the DPF is between the preset upper threshold temperature and the preset lower threshold temperature, whether the gradient of the current upstream temperature value of the DPF is continuously positive or negative, whether the time when the judgment result of the preset first time threshold is yes exceeds the third time threshold, or whether the vehicle mileage is greater than the preset distance threshold.

[0025] The temperature rise of the upstream DPF is the difference between the upstream DPF temperature and the upstream DPF temperature before regeneration.

[0026] Furthermore, when the judgment result of the third judgment module is not satisfied, the process returns to the first judgment module to determine whether the current upstream temperature value of the DPF is between the preset upper threshold temperature and the preset lower threshold temperature and whether the gradient of the current upstream temperature value of the DPF is continuously positive or negative and exceeds the preset first time threshold.

[0027] To achieve the above-mentioned technical objectives, this disclosure also provides a diesel engine that utilizes the steps in the above-described DPF removal diagnostic method.

[0028] To achieve the above-mentioned technical objectives, this disclosure also provides a vehicle equipped with the aforementioned diesel engine.

[0029] The beneficial effects of this disclosure are:

[0030] 1. By diagnosing DPF removal faults through the temperature difference before and after the DPF, the system eliminates the possibility of deviations in differential pressure measurements caused by factors such as post-treatment layout, differential pressure pipeline layout, and air leakage, thus improving diagnostic stability.

[0031] 2. Accurately identifies temperature rise or fall processes, and uses the highest DPF temperature difference rate calculated within that range for more precise judgment;

[0032] 3. Set the time and distance since the last monitoring status was set to 1 to effectively prevent frequent regeneration due to diagnostics. Attached Figure Description

[0033] Figure 1 A flowchart illustrating a diagnostic method for DPF removal according to an embodiment of the present invention is shown;

[0034] Figure 2 A schematic block diagram of a DPF removal diagnostic system according to an embodiment of the present invention is shown. Detailed Implementation

[0035] Embodiments of the present disclosure will now be described with reference to the accompanying drawings. However, it should be understood that these descriptions are exemplary only and are not intended to limit the scope of the disclosure. Furthermore, descriptions of well-known structures and technologies are omitted in the following description to avoid unnecessarily obscuring the concepts of the present disclosure.

[0036] The accompanying drawings illustrate various structural schematics according to embodiments of the present disclosure. These drawings are not to scale, and some details have been enlarged and may have been omitted for clarity. The shapes of the various regions and layers shown in the drawings, as well as their relative sizes and positional relationships, are merely exemplary and may deviate from reality due to manufacturing tolerances or technical limitations. Furthermore, those skilled in the art can design regions / layers with different shapes, sizes, and relative positions as needed.

[0037] Example 1:

[0038] like Figure 1 As shown:

[0039] This disclosure provides a diagnostic method for DPF removal, the method comprising:

[0040] A diagnostic method for DPF removal, the method comprising:

[0041] Obtain the current upstream temperature value and the current downstream temperature value of the DPF;

[0042] Determine whether the current upstream temperature value of the DPF is between a preset upper threshold temperature and a preset lower threshold temperature, and whether the gradient of the current upstream temperature value of the DPF is continuously positive or negative and exceeds a preset first time threshold.

[0043] If the conditions are met, the diesel engine power and diesel engine running time will be accumulated, and the DPF temperature difference rate will be calculated for each unit of time with each time step as the unit of time.

[0044] When the upstream temperature gradient of the DPF reaches 0, that is, when the continuous decrease or increase in temperature ends, the calculation of the DPF temperature difference rate ends.

[0045] Determine whether the cumulative engine power in the current interval is greater than the preset power threshold or the engine running time is greater than the second time threshold. If so, calculate the maximum value of the DPF temperature difference rate in each unit time in the current interval. If the maximum value of the DPF temperature difference rate in each unit time in the current interval is less than the preset temperature difference rate threshold, report a fault.

[0046] If the conditions are not met, the process continues to return to determining whether the current upstream temperature value of the DPF is between the preset upper threshold temperature and the preset lower threshold temperature, and whether the gradient of the current upstream temperature value of the DPF is continuously positive or negative and exceeds the preset first time threshold.

[0047] Furthermore, the calculation of the DPF temperature difference rate per unit time, with each time step as the unit of time, is specifically calculated according to the following formula: ρ = DPF temperature difference rate per unit time.

[0048] ρ = (DPF upstream temperature - DPF downstream temperature) / DPF downstream temperature.

[0049] Furthermore, if the condition exists, the maximum value of the DPF temperature difference rate per unit time within the current interval is calculated. If the maximum value of the DPF temperature difference rate per unit time within the current interval is greater than or equal to a preset temperature difference rate threshold, the method further includes:

[0050] If the determination result of whether the current upstream temperature value of the DPF is between the preset upper threshold temperature and the preset lower threshold temperature, and whether the gradient of the current upstream temperature value of the DPF is continuously positive or negative and exceeds the preset first time threshold, and whether the time exceeds the third time threshold or the vehicle mileage is greater than the preset distance threshold, then the regeneration mode is entered to increase the DPF temperature until the upstream temperature of the DPF increases to a temperature greater than the preset temperature threshold and continues to exceed the preset fourth time threshold for a period of time. Then the regeneration mode is exited and the process of determining whether the current upstream temperature value of the DPF is between the preset upper threshold temperature and the preset lower threshold temperature, and whether the gradient of the current upstream temperature value of the DPF is continuously positive or negative and exceeds the preset first time threshold is returned.

[0051] The temperature rise of the upstream DPF is the difference between the upstream DPF temperature and the upstream DPF temperature before regeneration.

[0052] Furthermore, when determining whether the current upstream temperature value of the DPF is between a preset upper threshold temperature and a preset lower threshold temperature, and whether the gradient of the current upstream temperature value of the DPF is continuously positive or negative and exceeds a preset first time threshold, if the determination result is yes, and the time exceeds a third time threshold, or if the determination result is no, and the vehicle's mileage is greater than a preset distance threshold, the process returns to determining whether the current upstream temperature value of the DPF is between a preset upper threshold temperature and a preset lower threshold temperature, and whether the gradient of the current upstream temperature value of the DPF is continuously positive or negative and exceeds a preset first time threshold.

[0053] When the following monitoring conditions are met:

[0054] 1. The upstream temperature of the DPF is between the preset upper threshold temperature T1 and the preset lower threshold temperature T2;

[0055] 2. The upstream temperature gradient of the DPF is continuously positive for more than t1 time or continuously negative for more than t1 time, that is, there is a sufficiently continuous temperature rise or temperature drop process.

[0056] 3. The DPF temperature sensor has no related faults.

[0057] When the above three conditions are met, the monitoring status is set to 1. At this point, engine power and operating time are accumulated, and a DPF temperature difference rate ρ is calculated at each time step.

[0058] ρ = (DPF upstream temperature - DPF downstream temperature) / DPF downstream temperature.

[0059] When the upstream temperature gradient of the DPF reaches zero, indicating the end of the continuous temperature rise or fall, the DPF temperature difference rate calculation is complete. The calculation then checks if the cumulative engine power within this interval is greater than P. thrAlternatively, if the engine running time is greater than t2, then calculate the maximum DPF temperature difference rate ρ for that interval. max When ρ max <ρ thr Then report the fault; if ρ max ≥ρ thr If the time since the last monitoring status was set to 1 exceeds the third time threshold t3 or the vehicle mileage is greater than L, then the regeneration mode needs to be entered to increase the DPF temperature. The regeneration mode will continue until the upstream temperature of the DPF (the difference between the upstream temperature of the DPF and the upstream temperature of the DPF before regeneration) is greater than T3 and lasts for the fourth time threshold t4. Then the regeneration mode will be exited, thereby creating the temperature rise conditions required in the monitoring conditions.

[0060] If the cumulative engine power is less than or equal to P thr If the engine running time is less than or equal to the second time threshold t2, or the time since the last monitoring status was set to 1 has not exceeded the third time threshold t3 and the engine running mileage has not exceeded L, then the monitoring condition judgment will be entered again.

[0061] Example 2:

[0062] like Figure 2 As shown:

[0063] To address the aforementioned technical problems, this disclosure also provides a DPF removal diagnostic system, the method of which includes:

[0064] Temperature acquisition module 201 is used to acquire the current upstream temperature value and the current downstream temperature value of the DPF.

[0065] The first judgment module 202 is used to determine whether the current upstream temperature value of the DPF is between a preset upper threshold temperature and a preset lower threshold temperature and whether the gradient of the current upstream temperature value of the DPF is continuously positive or negative and exceeds a preset first time threshold.

[0066] The second judgment module 203 is used to determine whether the cumulative engine power in the current interval is greater than a preset power threshold or the engine running time is greater than a second time threshold. If so, the maximum value of the DPF temperature difference rate in each unit time in the current interval is calculated. If the maximum value of the DPF temperature difference rate in each unit time in the current interval is less than the preset temperature difference rate threshold, a fault is reported.

[0067] Furthermore, the calculation of the DPF temperature difference rate per unit time, with each time step as the unit of time, is specifically calculated according to the following formula: ρ = DPF temperature difference rate per unit time.

[0068] ρ = (DPF upstream temperature - DPF downstream temperature) / DPF downstream temperature.

[0069] Furthermore, the system also includes:

[0070] The third judgment module is used to determine whether the current upstream temperature value of the DPF is between the preset upper threshold temperature and the preset lower threshold temperature, whether the gradient of the current upstream temperature value of the DPF is continuously positive or negative, whether the time when the judgment result of the preset first time threshold is yes exceeds the third time threshold, or whether the vehicle mileage is greater than the preset distance threshold.

[0071] The temperature rise of the upstream DPF is the difference between the upstream DPF temperature and the upstream DPF temperature before regeneration.

[0072] Furthermore, when the judgment result of the third judgment module is not satisfied, the process returns to the first judgment module to determine whether the current upstream temperature value of the DPF is between the preset upper threshold temperature and the preset lower threshold temperature and whether the gradient of the current upstream temperature value of the DPF is continuously positive or negative and exceeds the preset first time threshold.

[0073] Example 3:

[0074] To achieve the above-mentioned technical objectives, this disclosure also provides a diesel engine equipped with the above-mentioned DPF removal diagnostic system and utilizing the steps in the above-mentioned DPF removal diagnostic method.

[0075] Example 4:

[0076] To achieve the above-mentioned technical objectives, this disclosure also provides a vehicle equipped with the aforementioned diesel engine.

[0077] The embodiments of this disclosure have been described above. However, these embodiments are for illustrative purposes only and are not intended to limit the scope of this disclosure. The scope of this disclosure is defined by the appended claims and their equivalents. Various substitutions and modifications can be made by those skilled in the art without departing from the scope of this disclosure, and all such substitutions and modifications should fall within the scope of this disclosure.

Claims

1. A diagnostic method for DPF removal, characterized in that, The method includes: Obtain the current upstream temperature value and the current downstream temperature value of the DPF; Determine whether the current upstream temperature value of the DPF is between a preset upper threshold temperature and a preset lower threshold temperature, and whether the gradient of the current upstream temperature value of the DPF is continuously positive or negative and exceeds a preset first time threshold. If the conditions are met, the diesel engine power and diesel engine running time will be accumulated, and the DPF temperature difference rate will be calculated for each unit of time with each time step as the unit of time. When the upstream temperature gradient of the DPF reaches 0, that is, when the continuous decrease or increase in temperature ends, the calculation of the DPF temperature difference rate ends. Determine whether the cumulative engine power in the current interval is greater than the preset power threshold or the engine running time is greater than the second time threshold. If so, calculate the maximum value of the DPF temperature difference rate in each unit time in the current interval. If the maximum value of the DPF temperature difference rate in each unit time in the current interval is less than the preset temperature difference rate threshold, report a fault. If the conditions are not met, the process continues to return to determining whether the current upstream temperature value of the DPF is between the preset upper threshold temperature and the preset lower threshold temperature, and whether the gradient of the current upstream temperature value of the DPF is continuously positive or negative and exceeds the preset first time threshold.

2. The method according to claim 1, characterized in that, The calculation of the DPF temperature difference rate per unit time, with each time step as the unit of time, is specifically calculated according to the following formula: ρ = (DPF upstream temperature - DPF downstream temperature) / DPF downstream temperature.

3. The method according to claim 1, characterized in that, If such a condition exists, then the maximum value of the DPF temperature difference rate per unit time within the current interval is calculated. If the maximum value of the DPF temperature difference rate per unit time within the current interval is greater than or equal to a preset temperature difference rate threshold, then the method further includes: If the determination result of whether the current upstream temperature value of the DPF is between the preset upper threshold temperature and the preset lower threshold temperature, and whether the gradient of the current upstream temperature value of the DPF is continuously positive or negative and exceeds the preset first time threshold, and whether the time exceeds the third time threshold or the vehicle mileage is greater than the preset distance threshold, then the regeneration mode is entered to increase the DPF temperature until the upstream temperature of the DPF increases to a temperature greater than the preset temperature threshold and continues to exceed the preset fourth time threshold for a period of time. Then the regeneration mode is exited and the process of determining whether the current upstream temperature value of the DPF is between the preset upper threshold temperature and the preset lower threshold temperature, and whether the gradient of the current upstream temperature value of the DPF is continuously positive or negative and exceeds the preset first time threshold is returned. The temperature rise of the upstream DPF is the difference between the upstream DPF temperature and the upstream DPF temperature before regeneration.

4. The method according to claim 3, characterized in that, If the determination of whether the current upstream temperature value of the DPF is between the preset upper threshold temperature and the preset lower threshold temperature and whether the gradient of the current upstream temperature value of the DPF is continuously positive or negative and exceeds the preset first time threshold is true, or if the determination of whether the vehicle mileage is greater than the preset distance threshold is false, the process of determining whether the current upstream temperature value of the DPF is between the preset upper threshold temperature and the preset lower threshold temperature and whether the gradient of the current upstream temperature value of the DPF is continuously positive or negative and exceeds the preset first time threshold is returned.

5. A DPF removal diagnostic system, characterized in that, include: The temperature acquisition module is used to obtain the current upstream temperature value and the current downstream temperature value of the DPF. The first judgment module is used to determine whether the current upstream temperature value of the DPF is between a preset upper threshold temperature and a preset lower threshold temperature and whether the gradient of the current upstream temperature value of the DPF is continuously positive or negative and exceeds a preset first time threshold. The second judgment module is used to determine whether the cumulative engine power in the current interval is greater than a preset power threshold or the engine running time is greater than a second time threshold. If so, the maximum value of the DPF temperature difference rate in each unit time in the current interval is calculated. If the maximum value of the DPF temperature difference rate in each unit time in the current interval is less than the preset temperature difference rate threshold, a fault is reported.

6. The system according to claim 5, characterized in that, The calculation of the DPF temperature difference rate per unit time, with each time step as the unit of time, is specifically calculated according to the following formula: ρ = (DPF upstream temperature - DPF downstream temperature) / DPF downstream temperature.

7. The system according to claim 5, characterized in that, The system also includes: The third judgment module is used to determine whether the current upstream temperature value of the DPF is between the preset upper threshold temperature and the preset lower threshold temperature, whether the gradient of the current upstream temperature value of the DPF is continuously positive or negative, whether the time when the judgment result of the preset first time threshold is yes exceeds the third time threshold, or whether the vehicle mileage is greater than the preset distance threshold. The temperature rise of the upstream DPF is the difference between the upstream DPF temperature and the upstream DPF temperature before regeneration.

8. The system according to claim 7, characterized in that, When the judgment result of the third judgment module is not satisfied, the process returns to the first judgment module to determine whether the current upstream temperature value of the DPF is between the preset upper threshold temperature and the preset lower threshold temperature and whether the gradient of the current upstream temperature value of the DPF is continuously positive or negative and exceeds the preset first time threshold.

9. A diesel engine, characterized in that, The steps of the DPF removal diagnostic method as described in any one of claims 1 to 4 are utilized.

10. A vehicle, characterized in that, The vehicle is equipped with the diesel engine as described in claim 9.

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