Method and apparatus for determining failure of an egr system

Abstract

The application discloses a fault determination method and device of an EGR system. The method comprises the following steps: obtaining an ambient temperature of an exhaust gas recirculation (EGR) system of a target vehicle and an engine water temperature corresponding to the EGR system; determining whether the EGR system meets preset enabling conditions when the ambient temperature and the engine water temperature meet preset conditions; obtaining an upstream pipe pressure corresponding to an EGR valve in the EGR system and a downstream pipe pressure corresponding to the EGR valve when the EGR system meets the preset enabling conditions; and determining whether the EGR system has a fault according to the upstream pipe pressure corresponding to the EGR valve and the downstream pipe pressure corresponding to the EGR valve. The method provided in the application at least solves the technical problem that a fault determination process of an EGR system in the related art is complex, thereby reducing the fault determination efficiency.

Description

Technical Field

[0001] This application relates to the field of vehicle fault detection technology, and more specifically, to a fault determination method and apparatus for an EGR system. Background Technology

[0002] Exhaust Gas Recirculation (EGR) technology has become a key solution for reducing nitrogen oxide emissions, optimizing combustion processes, and improving fuel economy. The EGR differential pressure sensor, as a core component of the EGR control system, is responsible for real-time acquisition of the pressure difference signal across the valve and accurate feedback of the exhaust gas recirculation status, providing data for the system to precisely control the exhaust gas recirculation rate. If this sensor malfunctions, it will directly cause distortion in EGR rate control and inaccurate exhaust gas flow control, leading to a series of problems such as poor combustion, reduced power, excessive emissions, and decreased vehicle reliability. Therefore, EGR differential pressure sensor fault diagnosis is crucial. Existing EGR differential pressure sensor fault detection primarily diagnoses signal jamming, icing, and faults in the differential pressure sensor's pressure tapping pipeline. For example, it uses exhaust flow and pressure signals to determine if a differential pressure sensor signal jamming is present; a complete process of icing identification, de-icing control, and recovery monitoring enables accurate diagnosis and handling of sensor icing issues in high-altitude and cold regions; and it calculates corresponding energy ratios based on measured pressures and differential pressures before and after the EGR valve, comparing these energy ratios with corresponding thresholds, and combining this with the fault count recorded by a fault counter to determine if a fault exists in the pressure tapping pipeline. However, these technologies require building pressure models and performing complex model pressure and energy calculations, leading to a complex fault determination process for EGR systems and resulting in low fault determination efficiency. Summary of the Invention

[0003] This application provides a method and apparatus for determining faults in an EGR system, which at least solves the technical problem in the related art that the fault determination process of an EGR system is complex, resulting in low fault determination efficiency.

[0004] According to one aspect of the embodiments of this application, a fault determination method for an EGR system is provided, comprising: acquiring the ambient temperature of the exhaust gas recirculation (EGR) system of a target vehicle and the engine coolant temperature corresponding to the EGR system; if the ambient temperature and the engine coolant temperature meet preset conditions, determining whether the EGR system meets preset enabling conditions; if the EGR system meets the preset enabling conditions, acquiring the upstream pipe pressure corresponding to the EGR valve and the downstream pipe pressure corresponding to the EGR valve in the EGR system; and determining whether the EGR system has a fault based on the upstream pipe pressure corresponding to the EGR valve and the downstream pipe pressure corresponding to the EGR valve.

[0005] Optionally, the method further includes: when the ambient temperature is within a preset range, acquiring the engine coolant temperature; when the engine coolant temperature is greater than a preset coolant temperature and the duration is greater than a first duration, determining that the ambient temperature and the engine coolant temperature meet preset conditions.

[0006] Optionally, the method further includes: acquiring the status information of the differential pressure sensor in the EGR system, the running time of the engine, the engine speed, and the engine load value respectively; and determining that the EGR system meets the preset enabling conditions when the status information of the differential pressure sensor in the EGR system indicates that the circuit corresponding to the differential pressure sensor is fault-free and the upstream and downstream pressure signals of the differential pressure sensor are reliable, the running time of the engine is greater than a second duration, the engine speed is greater than a preset speed, and the engine load value is greater than a preset load value.

[0007] Optionally, determining whether the EGR system is faulty based on the upstream pipeline pressure corresponding to the EGR valve and the downstream pipeline pressure corresponding to the EGR valve includes: obtaining the difference between the upstream pipeline pressure corresponding to the EGR valve and the downstream pipeline pressure corresponding to the EGR valve, the rate of change of the upstream pipeline pressure, and the rate of change of the downstream pipeline pressure; and determining whether the EGR system is faulty based on the difference, the rate of change of the upstream pipeline pressure, and the rate of change of the downstream pipeline pressure.

[0008] Optionally, determining whether the EGR system is faulty based on the difference, the upstream pipeline pressure change rate, and the downstream pipeline pressure change rate includes: determining that the EGR system is faulty if the difference is less than a first threshold; if the EGR system is faulty, obtaining the difference between the absolute values ​​of the upstream pipeline pressure change rate and the downstream pipeline pressure change rate; and determining whether there is a reverse connection fault in the pipeline connected to the differential pressure sensor in the EGR system based on the difference in absolute values.

[0009] Optionally, determining whether there is a reverse connection fault in the pipeline connected to the differential pressure sensor in the EGR system based on the difference in absolute values ​​includes: determining that there is a reverse connection fault in the pipeline of the differential pressure sensor in the EGR system if the difference in absolute values ​​is less than a second threshold.

[0010] Optionally, if it is determined that there is a reverse connection fault in the pipeline of the differential pressure sensor in the EGR system, the method further includes: outputting fault information, wherein the fault information includes at least a fault code indicating that there is a reverse connection fault in the pipeline of the differential pressure sensor.

[0011] According to another aspect of the embodiments of this application, a fault determination device for an EGR system is also provided, comprising: a first acquisition module, configured to acquire the ambient temperature of the exhaust gas recirculation (EGR) system of a target vehicle and the engine coolant temperature corresponding to the EGR system; a constraint module, configured to determine whether the EGR system meets preset enabling conditions when the ambient temperature and the engine coolant temperature meet preset conditions; a second acquisition module, configured to acquire the upstream pipe pressure corresponding to the EGR valve and the downstream pipe pressure corresponding to the EGR valve in the EGR system when the EGR system meets the preset enabling conditions; and a determination module, configured to determine whether the EGR system has a fault based on the upstream pipe pressure corresponding to the EGR valve and the downstream pipe pressure corresponding to the EGR valve.

[0012] A vehicle, characterized in that it comprises: a memory and a processor, wherein the memory is used to store program instructions; the processor, connected to the memory, is used to execute the fault determination method of the EGR system described above.

[0013] According to another aspect of the embodiments of this application, a computer program product is also provided, including computer instructions, characterized in that the computer instructions, when executed by a processor, implement the above-described fault determination method for the EGR system.

[0014] In this embodiment, the ambient temperature of the target vehicle's Exhaust Gas Recirculation (EGR) system and the engine coolant temperature corresponding to the EGR system are obtained. If the ambient temperature and engine coolant temperature meet preset conditions, it is determined whether the EGR system meets preset enabling conditions. If the EGR system meets the preset enabling conditions, the upstream pipe pressure and downstream pipe pressure corresponding to the EGR valve in the EGR system are obtained. The presence of a fault in the EGR system is determined based on these pressures. This method simplifies the detection process, improves fault detection efficiency, and solves the technical problem of complex fault determination processes in related technologies, leading to low fault determination efficiency. Attached Figure Description

[0015] The accompanying drawings, which are included to provide a further understanding of this application and form part of this application, illustrate exemplary embodiments and are used to explain this application, but do not constitute an undue limitation of this application. In the drawings:

[0016] Figure 1This is a hardware structure block diagram of a computer target terminal for implementing a fault determination method for an EGR system according to an embodiment of this application.

[0017] Figure 2 This is a flowchart of a fault determination method for an EGR system according to an embodiment of this application;

[0018] Figure 3 This is a schematic diagram of an EGR system structure according to an embodiment of this application;

[0019] Figure 4 This is a flowchart of another fault determination method for an EGR system according to an embodiment of this application;

[0020] Figure 5 This is a flowchart of another fault determination method for an EGR system according to an embodiment of this application;

[0021] Figure 6 This is a structural diagram of a fault determination device for an EGR system according to an embodiment of this application. Detailed Implementation

[0022] 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.

[0023] 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 so that the embodiments of this application described herein can be implemented in orders other than those illustrated or 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.

[0024] In related technologies, EGR differential pressure sensor fault detection mainly diagnoses signal jamming, icing, and faults in the differential pressure sensor's pressure tapping pipeline. For example, it may use exhaust flow and pressure signals to determine if a differential pressure sensor signal jamming fault exists; or it may employ a complete process of "icing identification - de-icing control - recovery monitoring" to diagnose and address sensor icing issues in high-altitude and cold regions; or it may calculate the corresponding energy ratios based on the measured pressures and differential pressures before and after the EGR valve, and then compare these energy ratios with corresponding thresholds, combined with the fault count recorded by a fault counter, to determine if there is a fault in the pressure tapping pipeline. However, this requires complex model pressure and energy ratio calculations, making the detection process complicated.

[0025] To address the problems existing in related technologies, this application provides a fault determination method for an EGR system, which can be run in... Figure 1 The computer target terminal shown will be explained below.

[0026] The fault determination method for the EGR system provided in this application can be executed in a mobile target terminal, a computer target terminal, or a similar computing device. Figure 1 A hardware block diagram of a computer target terminal for implementing a fault determination method for an EGR system is shown. Figure 1 As shown, the computer target terminal 10 may include one or more processors (shown as 102a, 102b, ..., 102n in the figure) (the processor may include, but is not limited to, a microprocessor MCU or a programmable logic device FPGA, etc.), a memory 104 for storing data, and a transmission module 106 for communication functions connected via wired and / or wireless networks. In addition, it may also include: a display, a keyboard, a cursor control device, an input / output interface (I / O interface), a universal serial bus (USB) port (which may be included as one of the ports of the I / O interface), a network interface, and a BUS bus. 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 aforementioned electronic device. For example, the computer target terminal 10 may also include... Figure 1 The more or fewer components shown, or having the same Figure 1 The different configurations shown.

[0027] It should be noted that the aforementioned one or more processors and / or other data processing circuits are generally referred to herein as "data processing circuits". These data processing circuits may be implemented wholly or partially as software, hardware, firmware, or any other combination thereof. Furthermore, the data processing circuits may be a single, independent processing module, or may be wholly or partially integrated into any other element in the computer target terminal 10. As involved in the embodiments of this application, the data processing circuits serve as a processor control mechanism (e.g., selection of a variable resistor target terminal path connected to an interface).

[0028] The memory 104 can be used to store software programs and modules of application software, such as the program instructions / data storage device corresponding to the fault determination method of the EGR system in this embodiment of the application. The processor executes various functional applications and data processing by running the software programs and modules stored in the memory 104, thereby realizing the fault determination method of the EGR system described above. The memory 104 may include high-speed random access memory, and may also include 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, and these remote memories can be connected to the computer target terminal 10 via a network. Examples of such networks include, but are not limited to, the Internet, corporate intranets, local area networks, mobile communication networks, and combinations thereof.

[0029] The transmission module 106 is used to receive or send data via a network. Specific examples of the network described above may include a wireless network provided by the communication provider of the computer target terminal 10. In one example, the transmission module 106 includes a Network Interface Controller (NIC), which can connect to other network devices via a base station to communicate with the Internet. In another example, the transmission module 106 may be a Radio Frequency (RF) module, used for wireless communication with the Internet.

[0030] The display can be, for example, a touchscreen liquid crystal display (LCD) that allows the user to interact with the user interface of the computer target terminal 10.

[0031] It should be noted here that, in some optional embodiments, the above... Figure 1 The computer target terminal shown may include hardware components (including circuitry), software components (including computer code stored on a computer-readable medium), or a combination of both hardware and software components. It should be noted that... Figure 1 This is only one instance of a specific particular instance, and is intended to illustrate the types of components that may exist in the aforementioned computer target terminal.

[0032] In the above operating environment, this application provides an embodiment of a fault determination method for an EGR system. 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.

[0033] Figure 2 This is a flowchart of a fault determination method for an EGR system according to an embodiment of this application, such as... Figure 2 As shown, the method includes the following steps:

[0034] Step S202: Obtain the ambient temperature of the exhaust gas recirculation (EGR) system of the target vehicle and the engine coolant temperature corresponding to the EGR system;

[0035] Step S204: If the ambient temperature and the engine coolant temperature meet the preset conditions, determine whether the EGR system meets the preset enabling conditions.

[0036] Step S206: When the EGR system meets the preset enabling conditions, obtain the upstream pipeline pressure corresponding to the EGR valve in the EGR system and the downstream pipeline pressure corresponding to the EGR valve.

[0037] Step S208: Determine whether there is a fault in the EGR system based on the upstream pipeline pressure corresponding to the EGR valve and the downstream pipeline pressure corresponding to the EGR valve.

[0038] like Figure 3 The diagram shown is a schematic of an engine EGR system. Figure 3As shown, the components include: TWC (Three-Way Catalytic Converter), GPF (Gasline Particulate Filter), C (compressor end), and T (turbine end). The EGR system draws a portion of the exhaust gas produced after engine combustion from the exhaust pipe, cools it in the EGR cooler, and then, controlled by the EGR valve, introduces it into the intake system according to the engine's operating conditions. There, it mixes with fresh air and enters the intake manifold and combustion chamber. The EGR differential pressure sensor measures the pressure upstream and downstream of the EGR valve and transmits this information to the engine control unit (ECU). The ECU calculates the recirculated exhaust gas flow rate and precisely controls the EGR valve opening to ensure optimal exhaust gas recirculation under various operating conditions. To determine if the EGR differential pressure sensor line is reversed, a specific operating condition can be selected for diagnostics. When the engine operates within a certain speed and load range, due to the throttling effect of the EGR valve, the upstream pressure of the EGR valve should be significantly higher than the downstream pressure. Meanwhile, since the upstream of the EGR is connected to the exhaust pipe, the upstream pressure of the EGR and the exhaust pressure change rapidly with the load when the engine load changes; while the downstream pressure of the EGR is connected to the booster intake pipe, and due to the function of the EGR valve, the upstream pressure of the EGR changes more slowly. Therefore, the rate of change of the upstream pressure of the EGR should be significantly higher than the rate of change of the downstream pressure of the EGR. Thus, the difference in the magnitude and rate of change of the pressure before and after the EGR can be used to diagnose the reverse connection fault of the EGR differential pressure sensor pipeline.

[0039] Through steps S202 to S208 of the above method, the ambient temperature of the target vehicle's Exhaust Gas Recirculation (EGR) system and the engine coolant temperature corresponding to the EGR system are obtained; if the ambient temperature and the engine coolant temperature meet preset conditions, it is determined whether the EGR system meets preset enabling conditions; if the EGR system meets the preset enabling conditions, the upstream pipe pressure and the downstream pipe pressure corresponding to the EGR valve in the EGR system are obtained; based on the upstream pipe pressure and the downstream pipe pressure corresponding to the EGR valve, it is determined whether the EGR system has a fault. By determining whether a fault exists through the upstream pipe pressure and the downstream pipe pressure corresponding to the EGR valve, the detection process is simplified, the fault detection efficiency is improved, and the technical problem of complex fault determination process of EGR system in related technologies, resulting in low fault determination efficiency, is solved.

[0040] In some embodiments of this application, when the ambient temperature is within a preset range, the engine coolant temperature is obtained; when the engine coolant temperature is greater than a preset coolant temperature and the duration is greater than a first duration, it is determined that the ambient temperature and the engine coolant temperature meet preset conditions.

[0041] The steps for determining whether the preset enabling conditions are met are as follows: The status information of the differential pressure sensor in the EGR system, the engine's operating time, the engine's speed, and the engine's load value are obtained respectively; if the status information of the differential pressure sensor in the EGR system indicates that the circuit corresponding to the differential pressure sensor is fault-free and the upstream and downstream pressure signals of the differential pressure sensor are reliable, the engine's operating time is greater than the second duration, the engine's speed is greater than the preset speed, and the engine's load value is greater than the preset load value, then the EGR system is determined to meet the preset enabling conditions.

[0042] It should be noted that there are multiple ways to detect circuit faults corresponding to the differential pressure sensor. One possible method is to monitor the power supply voltage and grounding resistance of the EGR differential pressure sensor through a monitoring circuit. There are also multiple ways to verify the reliability of the upstream and downstream pressure signals of the differential pressure sensor, such as: verifying whether the upstream and downstream pressures of the EGR valve are within the sensor's range and satisfying the physical logic relationship that the upstream pressure is not less than the downstream pressure; determining whether the upstream and downstream pressures have dynamic response characteristics that change with engine load; and cross-validating the upstream pressure with the exhaust pressure sensor signal and the downstream pressure with the intake pressure sensor signal.

[0043] In some embodiments of this application, the specific steps for determining whether the EGR system is faulty based on the upstream pipeline pressure corresponding to the EGR valve and the downstream pipeline pressure corresponding to the EGR valve are as follows: obtaining the difference between the upstream pipeline pressure corresponding to the EGR valve and the downstream pipeline pressure corresponding to the EGR valve, the rate of change of the upstream pipeline pressure, and the rate of change of the downstream pipeline pressure; determining whether the EGR system is faulty based on the difference, the rate of change of the upstream pipeline pressure, and the rate of change of the downstream pipeline pressure.

[0044] The specific steps for determining whether the EGR system has a fault based on the difference, the upstream pipeline pressure change rate, and the downstream pipeline pressure change rate are as follows: Figure 4 As shown, the process includes: determining that the EGR system is faulty when the difference is less than a first threshold; obtaining the difference between the absolute values ​​of the pressure change rate of the upstream pipeline and the pressure change rate of the downstream pipeline when the EGR system is determined to be faulty; and determining whether there is a reverse connection fault in the pipeline connected to the differential pressure sensor in the EGR system based on the difference in absolute values.

[0045] In one alternative approach, the specific steps for determining whether there is a reverse connection fault in the pipeline connected to the differential pressure sensor in the EGR system based on the difference in absolute values ​​are as follows: if the difference in absolute values ​​is less than a second threshold, it is determined that there is a reverse connection fault in the pipeline of the differential pressure sensor in the EGR system.

[0046] If it is determined that there is a reverse connection fault in the pipeline of the differential pressure sensor in the EGR system, fault information is output, wherein the fault information includes at least a fault code indicating that there is a reverse connection fault in the pipeline of the differential pressure sensor.

[0047] like Figure 5 As shown, the environmental conditions are first assessed. According to regulations, when the ambient temperature is below a certain value (-10℃ in this example), the diagnosis is not performed. When the ambient temperature is within a certain range (-10≤T≤1.5 in this example), the engine coolant temperature must be determined to be above the calibrated threshold (60℃ in this example) for a duration of more than the calibrated threshold (60s in this example) before the diagnosis is performed to rule out the risk of differential pressure sensor icing. When the ambient temperature is above a certain value (1.5℃ in this example), the environmental conditions are met, and the next step of the assessment is performed directly. Next, the enabling conditions are determined, which mainly include the following four points: First, there must be no EGR differential pressure sensor circuit fault or unreliable upstream and downstream pressure signals from the EGR differential pressure sensor, to avoid misjudging a reverse connection fault in the EGR differential pressure sensor pipeline; second, the engine must have started and maintained this state for a certain period of time (1 second in this example) to avoid the impact of pressure fluctuations during startup; third, the engine speed must be greater than a threshold (800 rpm in this example); and fourth, the engine load must be greater than a threshold (50% in this example). Conditions three and four together determine the operating conditions for performing the diagnosis. Under these conditions, the upstream pressure of the EGR should be significantly greater than the downstream pressure of the EGR. When all four conditions are met simultaneously, the next diagnostic procedure is executed. The upstream and downstream pressures of the EGR are obtained through the EGR differential pressure sensor, and the difference between the two is calculated. When this difference is less than a threshold (-20 hPa in this example), an abnormality in the EGR differential pressure sensor pipeline is considered to exist. To further confirm the EGR differential pressure sensor pipeline reversal fault, it is necessary to calculate the rate of change of the upstream and downstream pressures of the EGR, and calculate the difference between the absolute values ​​of the rate of change (since the rate of change is negative when the pressure drops, the absolute value of the rate of change should be used for calculation). When the difference is less than the threshold (-1 hPa / s in this embodiment), it is considered that there is an EGR differential pressure sensor pipeline reversal fault, and the system reports the fault.

[0048] To better illustrate the fault determination method of the EGR system in this application embodiment, this application embodiment also provides a method for determining the reverse connection of the EGR differential pressure sensor pipeline, as follows:

[0049] First, environmental conditions are assessed. According to regulations, diagnostics are not performed when the ambient temperature is below a certain value (-10℃ in this example). When the ambient temperature is within a certain range (-10 ≤ T ≤ 1.5 in this example), diagnostics are performed only when the engine coolant temperature is above the calibrated threshold (60℃ in this example) and the duration reaches the calibrated threshold (60s in this example) to rule out the risk of differential pressure sensor icing. When the ambient temperature is above a certain value (1.5℃ in this example), the environmental conditions are met, and the next step of assessment is performed directly. Next, the enabling conditions are determined, which mainly include the following four points: First, there must be no EGR differential pressure sensor circuit fault or unreliable upstream and downstream pressure signals from the EGR differential pressure sensor, to avoid misjudging a reverse connection fault in the EGR differential pressure sensor pipeline; second, the engine must have started and maintained this state for a certain period of time (1 second in this example) to avoid the impact of pressure fluctuations during startup; third, the engine speed must be greater than a threshold (800 rpm in this example); and fourth, the engine load must be greater than a threshold (50% in this example). Conditions three and four together determine the operating conditions for performing the diagnosis. Under these conditions, the upstream pressure of the EGR should be significantly greater than the downstream pressure of the EGR. When all four conditions are met simultaneously, the next diagnostic procedure is executed. The upstream and downstream pressures of the EGR are obtained through the EGR differential pressure sensor, and the difference between the two is calculated. When this difference is less than a threshold (-20 hPa in this example), an abnormality in the EGR differential pressure sensor pipeline is considered to exist. To further confirm the EGR differential pressure sensor pipeline reversal fault, the rate of change of upstream and downstream pressure of the EGR needs to be calculated separately, and the difference between the absolute values ​​of the rate of change (since the rate of change is negative when the pressure drops, the absolute value of the rate of change should be used for calculation) should be calculated. When the difference is less than the threshold (-1 hPa / s in this example), it is considered that there is an EGR differential pressure sensor pipeline reversal fault, and the system reports the fault.

[0050] To better illustrate the fault determination method of the EGR system in this application embodiment, this application embodiment also provides a method for determining the reverse connection of the EGR differential pressure sensor pipeline, the specific steps of which are as follows:

[0051] Step 1: Obtain the current ambient temperature and determine if it meets the environmental conditions for differential pressure sensor diagnosis:

[0052] The current ambient temperature is compared with the first predetermined temperature (-10℃) and the second predetermined temperature (1.5℃). If the current ambient temperature is less than -10℃, the environmental conditions are not met, and the diagnostic process is terminated. If the current ambient temperature is greater than 1.5℃, the environmental conditions are met, and the process proceeds to the next step. If the current ambient temperature is between -10℃ and 1.5℃, the engine coolant temperature is further obtained to determine whether it is greater than the calibrated temperature (60℃) and whether the duration reaches the predetermined time (60 seconds). If both conditions are met, the environmental conditions are met, and the process proceeds to the next step. Otherwise, the diagnostic process is terminated. The process continues only when the environmental conditions are met; if they are not met, there are no further operations, and the diagnostic process is terminated.

[0053] Step 2: Acquire the engine operating status signal and determine whether the enable conditions for differential pressure sensor diagnosis are met:

[0054] First, determine if the EGR differential pressure sensor has a circuit fault or if the upstream and downstream pressure signals are unreliable. If either fault exists, the enabling condition is not met, and the diagnostic process terminates. If no fault exists, determine if the engine start has been completed and if the duration is greater than 1 second. If not, the diagnostic process terminates. If the condition is met, further determine if the engine speed is greater than a predetermined value (800 rpm) and if the engine load is greater than a predetermined value (50%). If both the speed and load are met, the enabling condition is met, and the process proceeds to the next step; otherwise, the diagnostic process terminates. The process continues only if the enabling condition is met; otherwise, there are no further operations, and the diagnostic process terminates.

[0055] Step 3: Collect real-time values ​​of the upstream and downstream pressures of the EGR valve using the EGR differential pressure sensor.

[0056] The real-time pressure values ​​of the upstream and downstream pipelines of the EGR valve are read through two independent pressure sensing channels of the EGR differential pressure sensor. The pressure unit is hectopascals (hPa). These two pressure values ​​are the sole input source for subsequent calculations of pressure difference and rate of change.

[0057] Step 4: Calculate the pressure difference between the upstream and downstream of the EGR valve, and determine if there is any pipeline abnormality.

[0058] The pressure difference is obtained by subtracting the downstream pressure from the upstream pressure of the EGR valve. This pressure difference is then compared with a preset threshold (-20 hPa). If the pressure difference is less than -20 hPa, the EGR differential pressure sensor detection result is considered abnormal, and the process proceeds to the next step. If the pressure difference is greater than or equal to -20 hPa, no pipeline abnormality is considered, and the diagnostic process terminates. The process continues only when an abnormality is detected. If the result is normal, no further operations are performed, and the diagnostic process terminates.

[0059] Step 5: Calculate the absolute values ​​of the rates of change of pressure upstream and downstream of the EGR valve, and obtain the difference between them:

[0060] The upstream pressure change rate is obtained by performing a difference operation between the current upstream pressure value of the EGR valve and the upstream pressure value of the EGR valve in the previous sampling period; the downstream pressure change rate is obtained by performing a difference operation between the current downstream pressure value of the EGR valve and the downstream pressure value of the EGR valve in the previous sampling period; the absolute values ​​of the upstream and downstream pressure change rates are then taken respectively; finally, the difference between the absolute values ​​of the upstream and downstream pressure change rates is calculated.

[0061] Step 6: Based on the difference in the absolute value of the pressure change rate, determine whether there is a reverse connection fault in the EGR differential pressure sensor pipeline:

[0062] The difference is compared with a preset threshold (-1 hPa / s). If the difference is less than -1 hPa / s, the EGR differential pressure sensor pipeline is determined to have a reverse connection fault. If the difference is greater than or equal to -1 hPa / s, no reverse connection fault is determined, and the diagnostic process is terminated. When a fault is determined, the "EGR differential pressure sensor pipeline reverse connection" fault code is recorded and reported in the on-board diagnostic system. When a normal condition is determined, no fault recording is triggered, and the diagnostic process ends.

[0063] Step 7: When a pipe reversal fault is determined, trigger the fault storage and alarm mechanism:

[0064] Write the "EGR differential pressure sensor pipeline reverse connection" fault code into the non-volatile memory, illuminate the instrument panel fault indicator light, and send the fault information to the vehicle diagnostic system via the CAN bus.

[0065] Figure 6 A fault determination apparatus for an EGR system is shown, the apparatus comprising:

[0066] The first acquisition module 60 is used to acquire the ambient temperature of the exhaust gas recirculation (EGR) system of the target vehicle and the engine water temperature corresponding to the EGR system.

[0067] Constraint module 62 is used to determine whether the EGR system meets preset enabling conditions when the ambient temperature and the engine coolant temperature meet preset conditions;

[0068] The second acquisition module 64 is used to acquire the upstream pipeline pressure and the downstream pipeline pressure corresponding to the EGR valve in the EGR system when the EGR system meets the preset enabling conditions.

[0069] The determination module 66 is used to determine whether there is a fault in the EGR system based on the upstream pipeline pressure corresponding to the EGR valve and the downstream pipeline pressure corresponding to the EGR valve.

[0070] The aforementioned EGR system fault determination device acquires the ambient temperature of the target vehicle's Exhaust Gas Recirculation (EGR) system and the corresponding engine coolant temperature. If the ambient temperature and engine coolant temperature meet preset conditions, it determines whether the EGR system meets preset enabling conditions. If the EGR system meets the preset enabling conditions, it acquires the upstream and downstream pipe pressures corresponding to the EGR valve in the EGR system. Based on these upstream and downstream pipe pressures, it determines whether a fault exists in the EGR system. This method simplifies the detection process, improves fault detection efficiency, and solves the technical problem of complex fault determination processes leading to low fault determination efficiency in related technologies.

[0071] The fault determination device of the above-mentioned EGR system further includes: an environmental judgment submodule, used to obtain the engine coolant temperature when the ambient temperature is within a preset range; and to determine that the ambient temperature and the engine coolant temperature meet preset conditions when the engine coolant temperature is greater than the preset coolant temperature and the duration is greater than a first duration.

[0072] The fault determination device for the EGR system mentioned above further includes an enable condition judgment submodule, used to acquire the status information of the differential pressure sensor in the EGR system, the running time of the engine, the speed of the engine, and the load value of the engine respectively; and to determine that the EGR system meets the preset enable conditions when the status information of the differential pressure sensor in the EGR system indicates that the circuit corresponding to the differential pressure sensor is fault-free and the upstream and downstream pressure signals of the differential pressure sensor are reliable, the running time of the engine is greater than a second duration, the speed of the engine is greater than a preset speed, and the load value of the engine is greater than a preset load value.

[0073] The determination module 56 includes a determination submodule, used to determine whether there is a fault in the EGR system based on the upstream pipeline pressure corresponding to the EGR valve and the downstream pipeline pressure corresponding to the EGR valve, including: obtaining the difference between the upstream pipeline pressure corresponding to the EGR valve and the downstream pipeline pressure corresponding to the EGR valve, the rate of change of the upstream pipeline pressure and the rate of change of the downstream pipeline pressure; and determining whether there is a fault in the EGR system based on the difference, the rate of change of the upstream pipeline pressure and the rate of change of the downstream pipeline pressure.

[0074] The determination submodule includes a determination unit, used to determine whether the EGR system has a fault based on the difference, the upstream pipeline pressure change rate, and the downstream pipeline pressure change rate, including: determining that the EGR system has a fault when the difference is less than a first threshold; obtaining the difference between the absolute values ​​of the upstream pipeline pressure change rate and the downstream pipeline pressure change rate when the EGR system has a fault; and determining whether there is a reverse connection fault in the pipeline connected to the differential pressure sensor in the EGR system based on the difference in absolute values.

[0075] The determining unit includes a determining subunit, used to determine whether there is a reverse connection fault in the pipeline connected to the differential pressure sensor in the EGR system based on the difference in absolute values, including: determining that there is a reverse connection fault in the pipeline of the differential pressure sensor in the EGR system when the difference in absolute values ​​is less than a second threshold.

[0076] The fault determination device of the above-mentioned EGR system includes: an alarm submodule, used to output fault information when it is determined that there is a reverse connection fault in the pipeline of the differential pressure sensor in the EGR system, wherein the fault information includes at least: a fault code indicating that there is a reverse connection fault in the pipeline of the differential pressure sensor.

[0077] It should be noted that, Figure 6 The fault determination device of the EGR system shown is used to perform Figure 2 The fault determination method of the EGR system shown above also applies to the fault determination device of the EGR system, and will not be repeated here.

[0078] This application also provides a vehicle, including: a memory and a processor, wherein the memory is used to store program instructions; and the processor, connected to the memory, is used to execute the fault determination method of the EGR system described above.

[0079] This application also provides a computer program product, including computer instructions that, when executed by a processor, implement the steps of the fault determination method for the EGR system in this application.

[0080] The sequence numbers of the embodiments in this application are for descriptive purposes only and do not represent the superiority or inferiority of the embodiments.

[0081] In the above embodiments of this application, the descriptions of each embodiment have different focuses. For parts not described in detail in a certain embodiment, please refer to the relevant descriptions of other embodiments.

[0082] In the several embodiments provided in this application, it should be understood that the disclosed technical content can be implemented in other ways. The device embodiments described above are merely illustrative; for example, the division of units can be a logical functional division, and in actual implementation, there may be other division methods. For example, multiple units or components may be combined or integrated into another system, or some features may be ignored or not executed. Furthermore, the displayed or discussed mutual couplings, direct couplings, or communication connections may be through some interfaces; indirect couplings or communication connections between units or modules may be electrical or other forms.

[0083] The units described as separate components may or may not be physically separate. The components shown as units may or may not be physical units; that is, they may be located in one place or distributed across multiple units. Some or all of the units can be selected to achieve the purpose of this embodiment according to actual needs.

[0084] Furthermore, the functional units in the various embodiments of this application can be integrated into one processing unit, or each unit can exist physically separately, or two or more units can be integrated into one unit. The integrated unit can be implemented in hardware or as a software functional unit.

[0085] If the integrated unit is implemented as a software functional unit and sold or used as an independent product, it can be stored in a computer-readable storage medium. Based on this understanding, the technical solution of this application, in essence, or the part that contributes to the prior art, or all or part of the technical solution, can be embodied in the form of a software product. This computer software product is stored in a storage medium and includes several instructions to cause a computer device (which may be a personal computer, server, or network device, etc.) to execute all or part of the steps of the methods of the various embodiments of this application. The aforementioned storage medium includes various media capable of storing program code, such as a USB flash drive, read-only memory (ROM), random access memory (RAM), portable hard drive, magnetic disk, or optical disk.

[0086] The above are merely preferred embodiments of this application. It should be noted that those skilled in the art can make various improvements and modifications without departing from the principles of this application, and these improvements and modifications should also be considered within the scope of protection of this application.

Claims

1. A fault determination method for an EGR system, characterized in that, include: Obtain the ambient temperature of the target vehicle's Exhaust Gas Recirculation (EGR) system and the corresponding engine coolant temperature of the EGR system; If the ambient temperature and the engine coolant temperature meet preset conditions, determine whether the EGR system meets preset enabling conditions; When the EGR system meets the preset enabling conditions, the upstream pipeline pressure corresponding to the EGR valve and the downstream pipeline pressure corresponding to the EGR valve in the EGR system are obtained. The presence of a fault in the EGR system is determined based on the upstream pipeline pressure corresponding to the EGR valve and the downstream pipeline pressure corresponding to the EGR valve.

2. The method according to claim 1, characterized in that, The method further includes: When the ambient temperature is within a preset range, the engine coolant temperature is obtained; If the engine coolant temperature is greater than the preset coolant temperature and the duration is greater than the first duration, it is determined that the ambient temperature and the engine coolant temperature meet the preset conditions.

3. The method according to claim 1, characterized in that, The method further includes: The status information of the differential pressure sensor in the EGR system, the running time of the engine, the speed of the engine, and the load value of the engine are obtained respectively. If the status information of the differential pressure sensor in the EGR system indicates that the circuit corresponding to the differential pressure sensor is fault-free and the upstream and downstream pressure signals of the differential pressure sensor are reliable, the engine's running length is greater than the second duration, the engine speed is greater than the preset speed, and the engine load value is greater than the preset load value, then the EGR system is determined to meet the preset enabling conditions.

4. The method according to claim 3, characterized in that, Determining whether the EGR system is faulty based on the upstream and downstream pipeline pressures corresponding to the EGR valve includes: The difference between the upstream pipeline pressure corresponding to the EGR valve and the downstream pipeline pressure corresponding to the EGR valve, the rate of change of the upstream pipeline pressure, and the rate of change of the downstream pipeline pressure are obtained. The presence of a fault in the EGR system is determined based on the difference, the rate of change of pressure in the upstream pipeline, and the rate of change of pressure in the downstream pipeline.

5. The method according to claim 4, characterized in that, Determining whether the EGR system is faulty based on the difference, the rate of change of pressure in the upstream pipeline, and the rate of change of pressure in the downstream pipeline includes: If the difference is less than a first threshold, it is determined that the EGR system is faulty; If a fault is found in the EGR system, the difference between the absolute values ​​of the pressure change rate of the upstream pipeline and the pressure change rate of the downstream pipeline is obtained; The difference in absolute values ​​is used to determine whether there is a reverse connection fault in the pipeline connecting the EGR system to the differential pressure sensor.

6. The method according to claim 5, characterized in that, Determining whether there is a reverse connection fault in the pipeline connected to the differential pressure sensor in the EGR system based on the difference in absolute values ​​includes: If the difference in absolute values ​​is less than a second threshold, it is determined that there is a reverse connection fault in the pipeline of the differential pressure sensor in the EGR system.

7. The method according to claim 6, characterized in that, If a reverse connection fault is found in the pipeline of the differential pressure sensor in the EGR system, the method further includes: Output fault information, wherein the fault information includes at least a fault code indicating that the differential pressure sensor pipeline has a reverse connection fault.

8. A fault determination device for an EGR system, characterized in that, include: The first acquisition module is used to acquire the ambient temperature of the exhaust gas recirculation (EGR) system of the target vehicle and the engine coolant temperature corresponding to the EGR system. The constraint module is used to determine whether the EGR system meets the preset enabling conditions when the ambient temperature and the engine coolant temperature meet the preset conditions. The second acquisition module is used to acquire the upstream pipeline pressure and the downstream pipeline pressure corresponding to the EGR valve in the EGR system when the EGR system meets the preset enabling conditions. The determination module is used to determine whether there is a fault in the EGR system based on the upstream pipeline pressure corresponding to the EGR valve and the downstream pipeline pressure corresponding to the EGR valve.

9. A computer program product comprising computer instructions, characterized in that, When the computer instructions are executed by the processor, they implement the fault determination method of the EGR system according to any one of claims 1 to 7.

10. A vehicle, characterized in that, include: A memory and a processor, wherein the memory is used to store program instructions; The processor, connected to the memory, is used to execute the fault determination method of the EGR system according to any one of claims 1 to 7.

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