Diagnostic method for a hybrid system engine differential pressure sensor and related device

Abstract

The present application belongs to the technical field of differential pressure sensor diagnosis, and provides a diagnosis method for a differential pressure sensor of a hybrid system engine and related equipment. The ratio of differential pressure and exhaust flow is used to determine the overload flow resistance, and the flow resistance difference value is obtained by the overload flow resistance and the preset calculation flow resistance. Then, the differential pressure sensor is diagnosed by comparing the flow resistance difference value and the flow resistance difference threshold value to determine whether the differential pressure sensor is accurate. The corresponding relationship between the differential pressure, the exhaust flow and the flow resistance is only related to the current carbon load and back pressure, and will not change due to the surrounding environmental conditions, thereby avoiding the inaccuracy of traditional technologies in judging the differential pressure under steady state conditions and parked regeneration conditions, and achieving the purpose of real-time judgment of the differential pressure sensor. At the same time, after the flow resistance difference value is corrected according to the flow resistance correction coefficient determined by the temperature and the exhaust flow, the differential pressure sensor is diagnosed again, thereby avoiding false alarms and other phenomena caused by the diesel particulate filter overload fault.

Description

Technical Field

[0001] This invention belongs to the field of differential pressure sensor diagnostic technology, and particularly relates to a diagnostic method and related equipment for differential pressure sensors in hybrid system engines. Background Technology

[0002] Diesel engines filter soot through a diesel particulate filter (DPF) system. During operation, the DPF system may experience overload faults. Diesel engines typically determine overload by monitoring the DPF system's differential pressure. However, the DPF differential pressure sensor is frequently affected by moisture interference, voltage fluctuations, and other issues, leading to measurement errors and false overload alarms. Therefore, diagnosing the differential pressure sensor during DPF system monitoring can prevent false overload alarms.

[0003] In traditional methods for diagnosing differential pressure sensors, the sensor drift is determined by comparing a preset threshold with the measured value under stable vehicle operating conditions or parking regeneration mode. However, with traditional technology, the preset threshold is difficult to determine at the vehicle level. The actual differential pressure on the vehicle is highly dependent on the surrounding environment, carbon load, and other conditions. In particular, changes in the surrounding environment can easily lead to misjudgments. Furthermore, both steady-state operating conditions and parking regeneration require the actual conditions of the vehicle, making it impossible to make judgments at any time. Summary of the Invention

[0004] To address the aforementioned problems, this invention proposes a diagnostic method and related equipment for differential pressure sensors in hybrid system engines. This invention utilizes the uniqueness of the flow resistance corresponding to differential pressure and exhaust flow rate to determine the differential pressure sensor, avoiding the inaccuracies of traditional techniques that rely on steady-state and parking regeneration conditions for differential pressure determination. Furthermore, it enables real-time judgment by the differential pressure sensor. Simultaneously, if the diagnostic result meets preset conditions, differential pressure sensor diagnosis is stopped; otherwise, the flow resistance difference is corrected using a flow resistance correction coefficient determined by temperature and exhaust flow rate, and differential pressure sensor diagnosis is performed again. The corrected flow resistance difference is used to determine whether a diesel particulate filter overload fault exists, thus avoiding false alarms caused by diesel particulate filter overload faults.

[0005] To achieve the above objectives, the present invention is implemented through the following technical solution:

[0006] In a first aspect, the present invention provides a diagnostic method for a differential pressure sensor in a hybrid system engine, comprising:

[0007] When an overload fault alarm occurs in the diesel particulate filter, the differential pressure sensor reading and the exhaust flow rate of the diesel particulate filter are obtained.

[0008] The overload flow resistance is determined based on the ratio of the pressure difference to the exhaust flow rate; the flow resistance difference is obtained by comparing the overload flow resistance with a preset calculated flow resistance; wherein the calculated flow resistance is the slope of a function fitted based on test data.

[0009] The differential pressure sensor is diagnosed by comparing the flow resistance difference value with the flow resistance difference threshold. If the diagnosis result meets the preset conditions, the differential pressure sensor diagnosis is stopped. Otherwise, the flow resistance difference value is corrected according to the flow resistance correction coefficient determined by the temperature and exhaust flow rate, and the differential pressure sensor diagnosis is performed again.

[0010] Furthermore, a differential pressure test cycle is performed. The hybrid system motor controls the engine to perform a cycle test according to a preset cycle. The differential pressure and exhaust flow rate are collected during the cycle test. A function graph is fitted based on the differential pressure and exhaust flow rate. The slope of the function is the calculated flow resistance.

[0011] Furthermore, the average of multiple pressure differential values ​​corresponding to the exhaust flow rate is calculated, and then the absolute value of the difference between each pressure differential value and the average value is calculated. Pressure differential values ​​whose absolute values ​​exceed a preset value are defined as outliers and deleted.

[0012] Furthermore, when determining the flow resistance difference threshold Δ, an adjustment factor is added. , The rate of change of the slope of the fitted function's graph is determined as follows:

[0013] ;

[0014] ;

[0015] in, To calculate flow resistance; The pressure difference and actual overload flow resistance corresponding to the exhaust flow rate value; The slope of the fitted function image corresponding to the overload fault; In the graph of the function At the preset position on the left, the slope of the preset distance point in the direction of increasing exhaust flow rate; In the graph of the function At the preset position on the right, the slope of the preset distance point in the direction of the decrease in exhaust flow rate.

[0016] Furthermore, based on the temperature before the overload point and the exhaust flow rate at the overload point, a flow resistance correction coefficient is obtained from a preset spectrum; the flow resistance correction value is obtained by multiplying the flow resistance difference and the flow resistance correction coefficient, and then the differential pressure sensor is diagnosed based on the flow resistance correction value.

[0017] Furthermore, if the flow resistance difference is less than the flow resistance difference threshold, it is considered an overload fault of the diesel particulate filter; otherwise, differential pressure sensor calibration is performed before differential pressure sensor diagnosis.

[0018] Secondly, the present invention also provides a diagnostic system for a differential pressure sensor in a hybrid system engine, comprising:

[0019] The data acquisition module is configured to acquire the differential pressure of the differential pressure sensor and the exhaust flow rate of the diesel particulate filter when the diesel particulate filter is overloaded and alarmed.

[0020] The flow resistance difference determination module is configured to: determine the overload flow resistance based on the ratio of the pressure difference to the exhaust flow rate; and obtain the flow resistance difference by comparing the overload flow resistance with a preset calculated flow resistance; wherein the calculated flow resistance is the slope of a function fitted based on test data.

[0021] The diagnostic module is configured to: diagnose the differential pressure sensor by comparing the flow resistance difference value with the flow resistance difference threshold; if the diagnostic result meets the preset conditions, the differential pressure sensor diagnosis is stopped; otherwise, the flow resistance difference value is corrected according to the flow resistance correction coefficient determined by the temperature and exhaust flow rate, and the differential pressure sensor diagnosis is performed again.

[0022] Thirdly, the present invention also provides a computer-readable storage medium having a computer program stored thereon, which, when executed by a processor, implements the steps of the diagnostic method for a differential pressure sensor of a hybrid system engine as described in the first aspect.

[0023] Fourthly, the present invention also provides an electronic device, including a memory, a processor, and a computer program stored in the memory and capable of running on the processor, wherein the processor executes the program to implement the steps of the diagnostic method for a differential pressure sensor of a hybrid system engine as described in the first aspect.

[0024] Fifthly, the present invention also provides a computer program product comprising a computer program that, when executed by a processor, implements the steps of the diagnostic method for a differential pressure sensor of a hybrid system engine as described in the first aspect.

[0025] Compared with the prior art, the beneficial effects of the present invention are as follows:

[0026] This invention determines the overload flow resistance by the ratio of differential pressure to exhaust flow rate. The flow resistance difference is obtained by comparing the overload flow resistance with a preset calculated flow resistance, where the calculated flow resistance is the slope of a function fitted from test data. Then, the differential pressure sensor is diagnosed by comparing the flow resistance difference with a flow resistance difference threshold to determine its accuracy. The correspondence between differential pressure, exhaust flow rate, and flow resistance is only related to the current carbon load and back pressure, and does not change due to surrounding environmental conditions. Utilizing the uniqueness of the flow resistance corresponding to differential pressure and exhaust flow rate avoids the inaccuracies of traditional technologies that use steady-state and parking regeneration conditions to determine differential pressure, and enables real-time judgment by the differential pressure sensor. Furthermore, if the diagnostic result meets preset conditions, the differential pressure sensor diagnosis stops; otherwise, the flow resistance difference is corrected using a flow resistance correction coefficient determined by temperature and exhaust flow rate, and the differential pressure sensor diagnosis is performed again. The corrected flow resistance difference is used to determine whether there is a diesel particulate filter overload fault, avoiding false alarms caused by diesel particulate filter overload faults. Attached Figure Description

[0027] The accompanying drawings, which form part of this embodiment, are used to provide a further understanding of this embodiment. The illustrative embodiments and their descriptions are used to explain this embodiment and do not constitute an improper limitation of this embodiment.

[0028] Figure 1 This is a framework diagram of the fault confirmation process in Embodiment 1 of the present invention;

[0029] Figure 2 This is a flowchart of the differential pressure sensor diagnostic process according to Embodiment 1 of the present invention;

[0030] Figure 3 This is a preset differential pressure cycle in Embodiment 1 of the present invention;

[0031] Figure 4 This is a schematic diagram of the fitting function image in Embodiment 1 of the present invention;

[0032] Figure 5 This is a schematic diagram of the slope in the function graph of Embodiment 1 of the present invention;

[0033] Figure 6 This is a flowchart of the differential pressure sensor calibration process in Embodiment 1 of the present invention. Detailed Implementation

[0034] The present invention will be further described below with reference to the accompanying drawings and embodiments.

[0035] It should be noted that the following detailed descriptions are exemplary and intended to provide further explanation of this application. Unless otherwise specified, all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art to which this application pertains.

[0036] Example 1:

[0037] When diagnosing the differential pressure sensor under stable vehicle operating conditions, the DPF differential pressure is compared with a preset threshold at engine idling and relative stability to determine the reliability of the DPF differential pressure sensor. The differential pressure measurement is then corrected based on the differential pressure deviation at idle. When diagnosing the differential pressure sensor in parking regeneration mode, the DPF differential pressure sensor is diagnosed in this mode, and the differential pressure measurement is compared with a preset threshold to determine its reliability. As described in the background section, regardless of whether differential pressure sensor diagnosis is performed under stable vehicle operating conditions or parking regeneration mode, the preset threshold is difficult to determine at the vehicle level. The actual differential pressure on the vehicle is highly dependent on factors such as the surrounding environment and carbon load. Using a single point for judgment can easily lead to misjudgment. Furthermore, both steady-state operating conditions and parking regeneration require actual vehicle conditions, making it impossible to make judgments at any time.

[0038] To address at least one of the aforementioned problems, this embodiment provides a diagnostic method for differential pressure sensors in hybrid system engines. The accuracy of the differential pressure sensor is determined by calculating the flow resistance based on the differential pressure and exhaust flow rate. The correspondence between differential pressure, exhaust flow rate, and flow resistance is only related to the current carbon load and back pressure, and does not change due to surrounding environmental conditions. Utilizing the uniqueness of the flow resistance corresponding to differential pressure and exhaust flow rate to determine the accuracy of the differential pressure sensor is more reasonable, avoiding the inaccuracies of traditional techniques that use steady-state conditions and parking regeneration conditions to determine differential pressure.

[0039] like Figure 1 As shown in this embodiment, a diagnostic method for a differential pressure sensor in a hybrid system engine is provided, comprising: when a diesel particulate filter overload fault alarm is triggered, acquiring the differential pressure of the differential pressure sensor and the exhaust flow rate of the diesel particulate filter; determining the overload flow resistance based on the ratio of the differential pressure to the exhaust flow rate; obtaining the flow resistance difference value by comparing the overload flow resistance with a preset calculated flow resistance; wherein the calculated flow resistance is the slope of a function fitted based on test data; diagnosing the differential pressure sensor by comparing the flow resistance difference value with a flow resistance difference threshold; if the diagnostic result meets preset conditions, stopping the differential pressure sensor diagnosis; otherwise, correcting the flow resistance difference value according to a flow resistance correction coefficient determined by temperature and exhaust flow rate, and then re-performing the differential pressure sensor diagnosis.

[0040] like Figure 2 and Figure 3 As shown, during differential pressure sensor diagnostics, a differential pressure test cycle is performed. The hybrid system's motor controls the engine to perform a cyclic test according to a preset differential pressure cycle. The differential pressure and exhaust flow signals are collected by the ECU (Electronic Control Unit). The preset differential pressure cycle represents the relationship between engine speed and engine load. Optionally, the preset differential pressure cycle can be as follows: Figure 3 As shown; a function graph is fitted based on the collected pressure difference and exhaust flow signals, and the slope of the function is calculated, which is the flow resistance k1; then the overload error point is run, and the corresponding overload flow resistance k2 is obtained based on the collected pressure difference. The flow resistance difference Δk is obtained by subtracting k2 from k1; the preset flow resistance difference threshold is found based on the collected exhaust flow, and the flow resistance difference Δk is compared with the flow resistance difference threshold to determine whether the measured pressure difference is too large or too small.

[0041] S1. Determination of flow resistance:

[0042] S1.1, Loop Test:

[0043] Multiple sets of exhaust flow rate values ​​and corresponding pressure difference values ​​were obtained through cyclic testing. Optionally, an exhaust flow rate of 100 m³ / s was selected. 2 / h、200m 2 / h, 300m 2 / h, 400m 2 / h, 500m 2 / h, 600m 2 / h, 700m 2 / h、800m 2 / h、900m 2 / h and 1000m 2 The pressure difference value corresponding to / h. Take multiple pressure difference values ​​corresponding to each exhaust flow rate value; for example, obtain multiple sets of exhaust flow rate values ​​of 100m³ / h through cyclic testing. 2 The pressure difference value corresponding to / h, for an exhaust flow rate of 100m³ / h 2 Multiple differential pressure values ​​corresponding to / h are processed by deleting outliers; optionally, the exhaust flow rate value of 100m³ is processed. 2 The average of multiple differential pressure values ​​corresponding to / h is calculated, and then the absolute value of the difference between each differential pressure value and the average value is calculated. Differential pressure values ​​whose absolute values ​​exceed the preset value are defined as outliers and deleted. The average of the multiple differential pressure values ​​after deletion is calculated again, and the result is used as the exhaust flow rate value of 100m³. 2 The differential pressure value corresponding to / h, and the differential pressure values ​​corresponding to other exhaust flow rates are all deleted as outliers.

[0044] S1.2. Fit the function graph to obtain the calculated flow resistance:

[0045] Using exhaust flow rate as the x-axis and pressure difference as the y-axis, a function graph is fitted using conventional fitting techniques to obtain a straight line with a fixed slope.

[0046] S2, Flow resistance difference threshold Determination:

[0047] Optional, such as Figure 4 and Figure 5As shown, by setting an overload fault test in the experiment, the pressure difference and actual overload flow resistance k3 corresponding to the exhaust flow rate value are obtained. The flow resistance difference threshold is obtained through k1-k3. .

[0048] In some other embodiments, in order to increase the flow resistance difference threshold The accuracy in determining the flow resistance difference threshold When, add a regulating factor , The rate of change of the slope of the fitted function graph is determined.

[0049] ;

[0050] ;

[0051] in, The slope of the fitted function image corresponding to the overload fault; In the graph of the function At a preset distance location near the left side, the slope of the preset distance point in the direction of increasing exhaust flow rate; In the graph of the function At a preset distance location near the right, the slope of the preset distance point in the direction of the decrease in exhaust flow rate; the preset distance can be determined based on the horizontal or vertical coordinate.

[0052] Understandably, errors in the fitted function graph, caused by factors such as the range of values ​​used during fitting and the fitting method, will affect the flow resistance difference threshold. This increases the risk of affecting the accuracy of differential pressure sensor diagnostics. In this embodiment, a dynamic adjustment factor is used to address this. The offsetting effect reduces the fitting error, thereby increasing the flow resistance difference threshold. This improves accuracy, thereby enhancing the diagnostic accuracy of differential pressure sensors.

[0053] S3. Comparison between flow resistance difference and flow resistance difference threshold:

[0054] Compare the flow resistance difference Δk with the flow resistance difference threshold. This is used to determine whether the measured pressure difference is too large or too small. Optionally, when the flow resistance difference value Δk is less than the flow resistance difference threshold... If the difference between the flow resistance difference Δk and the flow resistance difference threshold Δk is greater than a preset value, the measured pressure difference is judged to be too large. Similarly, if the difference between the flow resistance difference Δk and the flow resistance difference threshold Δk is less than a preset value, the measured pressure difference is judged to be too small.

[0055] like Figure 6As shown, when the measured differential pressure is too large, the differential pressure sensor is calibrated; optionally, the flow resistance correction coefficient is obtained by referring to the preset spectrum MAP based on the DPF temperature at the overload point and the exhaust flow rate at the overload point, and then the flow resistance correction value is obtained by multiplying the flow resistance difference Δk by the correction coefficient, and the carbon loading is calculated based on the flow resistance correction value.

[0056] Understandably, there is a one-to-one correspondence between pressure difference, flow resistance, and carbon loading; pressure difference calibration is based on the calculated flow resistance. Calibrate the pressure difference under different flow rates and temperatures. First, the pressure difference at the overload point can be used to obtain the actual flow resistance by adding the calculated flow resistance difference value to the overload flow resistance k2 at the overload point. Then, based on the actual flow resistance and gas flow resistance equations, the actual pressure difference is calculated back to obtain the pressure difference correction value at the overload point, thus completing the pressure difference calibration at that point. For other points with different temperatures and exhaust flow rates, it is generally believed that the drifting pressure difference sensor measurement value will deviate more significantly with increasing temperature and exhaust flow rate. Therefore, it is necessary to first obtain the flow resistance correction coefficient for different temperatures and exhaust flow rates by referring to the preset MAP based on the temperature and exhaust flow rate at the overload point. That is, the higher the temperature and exhaust flow rate at the actual operating point compared to the overload point temperature and exhaust flow rate, the larger the correction coefficient, and the greater the correction to the pressure difference value. The MAP can be used to calibrate the deviation at different temperatures and flow rates on the test bench. After obtaining the flow resistance correction coefficients at different actual temperatures and flow rates, the flow resistance correction value is obtained by multiplying the flow resistance difference Δk by the correction coefficient. Finally, the carbon loading is calculated based on the flow resistance correction value.

[0057] For example, suppose that at the overload point, the measured pressure difference deviation is 50% or 5 kPa obtained by calculating the actual flow resistance and actual pressure difference. However, at larger temperature and flow points, the deviation may be 70% or 8 kPa. Therefore, it is necessary to look up a flow resistance correction coefficient in the table to obtain the correction amount under different temperatures and flow rates to correct the pressure difference sensor.

[0058] Example 2:

[0059] This embodiment provides a diagnostic system for differential pressure sensors in hybrid system engines, including:

[0060] The data acquisition module is configured to acquire the differential pressure of the differential pressure sensor and the exhaust flow rate of the diesel particulate filter when the diesel particulate filter is overloaded and alarmed.

[0061] The flow resistance difference determination module is configured to: determine the overload flow resistance based on the ratio of the pressure difference to the exhaust flow rate; and obtain the flow resistance difference by comparing the overload flow resistance with a preset calculated flow resistance; wherein the calculated flow resistance is the slope of a function fitted based on test data.

[0062] The diagnostic module is configured to: diagnose the differential pressure sensor by comparing the flow resistance difference value with the flow resistance difference threshold; if the diagnostic result meets the preset conditions, the differential pressure sensor diagnosis is stopped; otherwise, the flow resistance difference value is corrected according to the flow resistance correction coefficient determined by the temperature and exhaust flow rate, and the differential pressure sensor diagnosis is performed again.

[0063] The operating method of the system is the same as the diagnostic method for the differential pressure sensor of the hybrid system engine in Example 1, and will not be repeated here.

[0064] Example 3:

[0065] This embodiment provides a computer-readable storage medium storing a computer program that, when executed by a processor, implements the steps of the diagnostic method for a differential pressure sensor of a hybrid system engine as described in Embodiment 1.

[0066] Example 4:

[0067] This embodiment provides an electronic device, including a memory, a processor, and a computer program stored in the memory and capable of running on the processor. When the processor executes the program, it implements the steps of the diagnostic method for a differential pressure sensor of a hybrid system engine described in Embodiment 1.

[0068] Example 5:

[0069] This embodiment provides a computer program product, which includes a computer program. When the computer program is executed by a processor, it implements the steps of the diagnostic method for differential pressure sensors of hybrid system engines described in Embodiment 1.

[0070] The above description is merely a preferred embodiment of this practice and is not intended to limit the scope of this practice. Various modifications and variations can be made to this practice by those skilled in the art. Any modifications, equivalent substitutions, or improvements made within the spirit and principles of this practice should be included within the protection scope of this practice.

Claims

1. A diagnostic method for a differential pressure sensor in a hybrid system engine, characterized in that, include: When an overload fault alarm occurs in the diesel particulate filter, the differential pressure sensor reading and the exhaust flow rate of the diesel particulate filter are obtained. When determining the flow resistance, a differential pressure test cycle is performed. The hybrid system motor controls the engine to perform a cyclic test according to a preset differential pressure cycle. Multiple sets of exhaust flow rates are collected during the cyclic test. Multiple differential pressure values ​​corresponding to each exhaust flow rate are taken. The average of the multiple differential pressure values ​​corresponding to the exhaust flow rate is calculated. Then, the absolute value of the difference between each differential pressure value and the average value is calculated. Differential pressure values ​​whose absolute values ​​exceed the preset value are defined as outliers and deleted to obtain the differential pressure corresponding to the exhaust flow rate. A function graph is fitted based on the differential pressure and exhaust flow rate. The slope of the function is the calculated flow resistance. The preset differential pressure cycle represents the relationship between engine speed and engine load. When an overload error occurs, the overload flow resistance is determined based on the ratio of the pressure difference to the exhaust flow rate. The flow resistance difference is obtained by comparing the overload flow resistance with a preset calculated flow resistance. The differential pressure sensor is diagnosed by comparing the flow resistance difference value and the flow resistance difference threshold. When the flow resistance difference value is less than the flow resistance difference threshold, it is identified as an overload fault of the diesel particulate filter. Otherwise, the differential pressure sensor is calibrated and then diagnosed. If the diagnostic results meet the preset conditions, the differential pressure sensor diagnostics are stopped; otherwise, the flow resistance correction coefficient is obtained from the preset spectrum based on the temperature before the overload point and the exhaust flow rate at the overload point; the flow resistance correction value is obtained by multiplying the flow resistance difference and the flow resistance correction coefficient; and the differential pressure sensor diagnostics are then performed based on the flow resistance correction value. The preset spectrum is used for deviation calibration of the test bench at different temperatures and flow rates. In determining the flow resistance difference threshold Δ, an adjustment factor β is added, and β is determined by the rate of change of the slope of the fitted function graph: Δ = k1 - (k3 + β); Where k1 is the calculated flow resistance; k3 is the pressure difference and actual overload flow resistance corresponding to the exhaust flow rate; I1 is the slope of the overload fault in the fitted function graph; I2 is the slope of the preset distance point in the direction of increasing exhaust flow rate at the preset position to the left of I1 in the function graph; and I3 is the slope of the preset distance point in the direction of decreasing exhaust flow rate at the preset position to the right of I1 in the function graph.

2. A diagnostic system for a differential pressure sensor in a hybrid system engine, characterized in that, include: The data acquisition module is configured to acquire the differential pressure of the differential pressure sensor and the exhaust flow rate of the diesel particulate filter when the diesel particulate filter is overloaded and alarmed. The flow resistance difference determination module is configured to: run an overload error point, determine the overload flow resistance based on the ratio of the pressure difference to the exhaust flow rate; and obtain the flow resistance difference value by comparing the overload flow resistance with the preset calculated flow resistance. The diagnostic module is configured to: diagnose the differential pressure sensor by comparing the flow resistance difference value and the flow resistance difference threshold value; wherein, if the flow resistance difference value is less than the flow resistance difference threshold value, it is identified as an overload fault of the diesel particulate filter; otherwise, the differential pressure sensor is calibrated before diagnostics are performed; if the diagnostic result meets preset conditions, differential pressure sensor diagnostics are stopped; otherwise, a flow resistance correction coefficient is obtained from a preset spectrum based on the temperature before the overload point and the exhaust flow rate at the overload point; a flow resistance correction value is obtained by multiplying the flow resistance difference value and the flow resistance correction coefficient; and differential pressure sensor diagnostics are then performed based on the flow resistance correction value. The preset spectrum is used for deviation calibration of the test bench at different temperatures and flow rates. In determining the flow resistance difference threshold Δ, an adjustment factor β is added, and β is determined by the rate of change of the slope of the fitted function graph: Δ = k1 - (k3 + β); Where k1 is the calculated flow resistance; k3 is the pressure difference and actual overload flow resistance corresponding to the exhaust flow rate; I1 is the slope of the overload fault in the fitted function graph; I2 is the slope of the preset distance point in the direction of increasing exhaust flow rate at the preset position to the left of I1 in the function graph; I3 is the slope of the preset distance point in the direction of decreasing exhaust flow rate at the preset position to the right of I1 in the function graph. The diagnostic system is also used to determine the calculated flow resistance by performing a differential pressure test cycle. The hybrid system motor controls the engine to perform a cycle test according to a preset differential pressure cycle. Multiple sets of exhaust flow rates are collected during the cycle test. Multiple differential pressure values ​​corresponding to each exhaust flow rate are taken. The average of the multiple differential pressure values ​​corresponding to the exhaust flow rate is calculated. Then, the absolute value of the difference between each differential pressure value and the average value is calculated. Differential pressure values ​​whose absolute values ​​exceed the preset value are defined as outliers and deleted to obtain the differential pressure corresponding to the exhaust flow rate. A function graph is fitted based on the differential pressure and exhaust flow rate. The slope of the function is the calculated flow resistance. The preset differential pressure cycle represents the relationship between engine speed and engine load.

3. A computer-readable storage medium having a computer program stored thereon, characterized in that, When executed by the processor, the program implements the steps of the diagnostic method for differential pressure sensors in hybrid system engines as described in claim 1.

4. An electronic device comprising a memory, a processor, and a computer program stored in the memory and capable of running on the processor, characterized in that, When the processor executes the program, it implements the steps of the diagnostic method for differential pressure sensors in hybrid system engines as described in claim 1.

5. A computer program product, characterized in that, The computer program product includes a computer program that, when executed by a processor, implements the steps of the diagnostic method for a differential pressure sensor of a hybrid system engine as described in claim 1.

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