Exhaust gas recirculation system fault detection method, device, storage medium and vehicle

Abstract

The present disclosure relates to an exhaust gas recirculation system fault detection method, device, storage medium and vehicle, belonging to the field of exhaust gas recirculation, the method comprising: determining the actual intake air pressure according to the current working condition of the engine; determining the first charging efficiency according to the actual intake air pressure and model parameters, the model parameters are determined according to the volume of the cylinder when the valve is closed, the standard intake air temperature, the actual intake air temperature, the standard atmospheric pressure and the engine displacement; determining the second charging efficiency according to the exhaust gas recirculation model mass and the fresh intake air mass; calculating the difference between the first charging efficiency and the second charging efficiency, and determining whether the exhaust gas recirculation system is faulty according to the difference. Using the charging efficiency instead of the air volume as the judgment basis can more accurately distinguish between faulty parts and normal parts, thereby avoiding false alarms or missed alarms.

Description

Technical Field

[0001] The present disclosure relates to the field of exhaust gas recirculation, and in particular, to an exhaust gas recirculation system fault detection method, device, storage medium and vehicle. Background Art

[0002] At present, diesel engine emission regulations are becoming increasingly stringent, among which the National VI regulations for light diesel vehicles have been implemented, and all exhaust emission pollutant limits are tightened. The main exhaust gas recirculation (EGR) system is used for in-engine purification. If the exhaust gas recirculation system components are damaged, the exhaust gas circulation control will not work properly, resulting in engine emissions being affected. Therefore, it is very important to monitor the exhaust gas recirculation system in real time, and it is necessary to diagnose whether the exhaust gas recirculation system is abnormal before the emissions exceed the standard.

[0003] In the related art, when the exhaust gas recirculation system monitors the control deviation of the air volume of the exhaust gas recirculation system, if the deviation value of the air volume exceeds the allowable range, it is determined that the exhaust gas recirculation system has a fault.

[0004] However, due to the large lateral range of the light vehicle's operation area (large speed range, small load range), the air volume deviation between a normal exhaust gas recirculation system and a faulty exhaust gas recirculation system is not clearly distinguishable, and false alarms and missed alarms are prone to occur. In addition, in plateau environments, due to the thin air, the intake volume is relatively small, and the control deviation value between normal parts and faulty parts is even less obvious. Therefore, light vehicles are more likely to have the risk of false alarms when operating in plateau high-altitude environments. Summary of the invention

[0005] In order to solve the problems existing in the related art, the present disclosure provides an exhaust gas recirculation system fault detection method, device, storage medium and vehicle.

[0006] In order to achieve the above-mentioned object, the present disclosure provides, in a first aspect, a method for detecting a fault in an exhaust gas recirculation system, the method comprising:

[0007] Determine the actual intake air pressure according to the current working condition of the engine;

[0008] Determining a first charging efficiency according to the actual intake air pressure and model parameters, wherein the model parameters are determined according to the volume of the cylinder when the valve is closed, the standard intake air temperature, the actual intake air temperature, the standard atmospheric pressure, and the engine displacement;

[0009] determining a second charging efficiency according to the exhaust gas recirculation model mass and the fresh intake air mass;

[0010] A difference between the first charging efficiency and the second charging efficiency is calculated, and whether an exhaust gas recirculation system fails is determined according to the difference.

[0011] Optionally, determining the actual intake pressure according to the current operating condition of the engine includes:

[0012] Determine the total intake pressure via a pressure sensor;

[0013] According to the current working condition of the engine, a pre-calibrated MAP is searched to determine the sum of the intake cylinder residual exhaust gas pressure and the gas return pressure corresponding to the current working condition;

[0014] The actual pressure entering the cylinder is determined as the total intake pressure minus the sum of the residual exhaust gas pressure in the intake cylinder and the gas return pressure.

[0015] Optionally, determining the second charging efficiency according to the current operating condition, the exhaust gas recirculation model mass, and the fresh intake air mass includes:

[0016] determining the exhaust gas recirculation model mass according to an upstream pressure and a downstream pressure of the exhaust gas recirculation valve and an effective cross-sectional area of ​​the exhaust gas recirculation valve;

[0017] Determining an actual intake air volume according to an ideal gas equation, the exhaust gas recirculation model mass, and the fresh intake air mass;

[0018] Determining a standard intake volume according to the total intake pressure, the speed corresponding to the current working condition, and the cylinder volume;

[0019] The second charging efficiency is obtained by dividing the actual intake volume by the standard intake volume.

[0020] Optionally, determining the first charging efficiency according to the actual intake air pressure and the model parameters includes:

[0021] determining a first product of a volume of the cylinder when the valve is closed and the standard intake air temperature;

[0022] Dividing the first product by a second product of the actual intake air temperature, the standard atmospheric pressure, and the engine displacement to obtain a model parameter;

[0023] The first charging efficiency is determined as a product of the model parameter and the actual intake pressure.

[0024] Optionally, determining whether the exhaust gas recirculation system is faulty according to the difference includes:

[0025] When the difference is greater than a first preset threshold, determining that a positive deviation fault exists in the exhaust gas recirculation system;

[0026] When the difference is less than a second preset threshold, determining that a negative deviation fault exists in the exhaust gas recirculation system;

[0027] The first preset threshold is greater than the second preset threshold.

[0028] Optionally, when the difference is greater than a first preset threshold, determining that a positive deviation fault exists in the exhaust gas recirculation system includes:

[0029] When the accumulated time duration during which the difference is greater than the first preset threshold exceeds a first preset time duration, determining that a positive deviation fault exists in the exhaust gas recirculation system;

[0030] When the difference is less than a second preset threshold, determining that a negative deviation fault exists in the exhaust gas recirculation system includes:

[0031] When the accumulated time duration during which the difference is less than the second preset threshold value exceeds the second preset time duration, it is determined that a negative deviation fault exists in the exhaust gas recirculation system.

[0032] Optionally, the method further comprises:

[0033] Determine whether a preset condition is met according to the current working condition of the vehicle, wherein the preset condition includes:

[0034] The engine speed of the vehicle is within a preset speed range;

[0035] The fuel injection amount of the vehicle is within a preset fuel injection amount range;

[0036] The exhaust gas recirculation system is in a closed-loop control state;

[0037] The opening of the exhaust gas recirculation valve is within a preset opening range;

[0038] Determining the actual intake air pressure according to the current working condition of the engine includes:

[0039] When it is determined that the current operating condition of the vehicle satisfies the preset condition, the actual intake air pressure is determined according to the current operating condition of the engine.

[0040] A second aspect of the present disclosure provides an exhaust gas recirculation system fault detection device, the device comprising:

[0041] A first determination module, used to determine an actual intake air pressure according to a current operating condition of the engine;

[0042] a second determination module, configured to determine a first charging efficiency according to the actual intake air pressure and a model parameter, wherein the model parameter is determined according to a volume of a cylinder when a valve is closed, a standard intake air temperature, an actual intake air temperature, a standard atmospheric pressure, and a displacement of the engine;

[0043] a third determination module, configured to determine a second charging efficiency according to the exhaust gas recirculation model mass and the fresh intake air mass;

[0044] The fourth determination module is used to calculate the difference between the first charging efficiency and the second charging efficiency, and determine whether the exhaust gas recirculation system is faulty according to the difference.

[0045] A third aspect of the present disclosure provides a non-temporary computer-readable storage medium having a computer program stored thereon, which, when executed by a processor, implements the steps of any one of the methods described in the first aspect of the present disclosure.

[0046] A fourth aspect of the present disclosure provides a vehicle, comprising an exhaust gas recirculation system, and an exhaust gas recirculation system fault detection device connected to the exhaust gas recirculation system, wherein the exhaust gas recirculation system fault detection device is used to execute any one of the methods described in the first aspect of the present disclosure.

[0047] Through the above technical solution, the first charging efficiency calculated by the actual pressure entering the cylinder does not change significantly when the exhaust gas recirculation system fails, while the second charging efficiency calculated based on the fresh intake air mass and the exhaust gas recirculation model mass changes significantly. Therefore, by comparing the first charging efficiency and the second charging efficiency to determine whether the exhaust gas recirculation system is faulty, and using the charging efficiency as the basis for judgment, it is possible to more accurately distinguish between faulty parts and normal parts, thereby avoiding false alarms or missed alarms.

[0048] Other features and advantages of the present disclosure will be described in detail in the following detailed description. BRIEF DESCRIPTION OF THE DRAWINGS

[0049] The accompanying drawings are used to provide a further understanding of the present disclosure and constitute a part of the specification. Together with the following specific embodiments, they are used to explain the present disclosure but do not constitute a limitation of the present disclosure. In the accompanying drawings:

[0050] Figure 1 is a flow chart showing a method for detecting a fault in an exhaust gas recirculation system according to an exemplary embodiment;

[0051] Figure 2 is another flow chart of an exhaust gas recirculation system fault detection method according to an exemplary embodiment;

[0052] Figure 3 is a block diagram of an exhaust gas recirculation system fault detection device according to an exemplary embodiment;

[0053] Figure 4 is a block diagram of an electronic device according to an exemplary embodiment;

[0054] Figure 5 is a block diagram of a vehicle according to an exemplary embodiment. DETAILED DESCRIPTION

[0055] The specific implementation of the present disclosure is described in detail below in conjunction with the accompanying drawings. It should be understood that the specific implementation described herein is only used to illustrate and explain the present disclosure, and is not used to limit the present disclosure.

[0056] In the related art, in some vehicle operation scenarios, such as in plateau environments and low-oxygen environments, the control deviation values ​​of normal parts and faulty parts based on the air volume are less obvious. Therefore, light vehicles are prone to the risk of false alarms when operating in such environments.

[0057] In order to solve the problems existing in the related art, an embodiment of the present disclosure provides an exhaust gas recirculation system fault detection method. Figure 1 The present invention is a flowchart of an exhaust gas recirculation system fault detection method according to an exemplary embodiment. The execution subject of the method may be an engine ECU (Electronic Control Unit) or other vehicle-mounted electronic equipment, which is not limited in the present disclosure. The method includes:

[0058] S101. Determine actual intake air pressure according to current engine operating conditions.

[0059] S102. Determine a first charging efficiency according to the actual intake pressure and model parameters, wherein the model parameters are determined according to the volume of the cylinder when the valve is closed, the standard intake temperature, the actual intake temperature, the standard atmospheric pressure, and the engine displacement.

[0060] Specifically, in some embodiments, determining the first charging efficiency according to the actual intake air pressure and the model parameters includes:

[0061] determining a first product of a volume of the cylinder when the valve is closed and the standard intake air temperature;

[0062] Dividing the first product by a second product of the actual intake air temperature, the standard atmospheric pressure, and the engine displacement to obtain a model parameter;

[0063] The first charging efficiency is determined as a product of the model parameter and the actual intake pressure.

[0064] Expressed in terms of formula, the first charging efficiency η vol1 According to the formula After calculation, the formula can be transformed to get Where m 实际Indicates the actual intake air mass, m 标准 Indicates the intake air quality under standard working conditions, V 实际 Indicates the volume of the cylinder when the valve is closed, T 标准 Indicates the standard intake air temperature, T 实际 Indicates the actual intake air temperature, P 标准 Indicates standard atmospheric pressure, V 标准 represents the engine displacement and R is the specific gas constant of dry air. It can be calibrated as the model parameter FAC. Based on this, the first charging efficiency can be determined according to the actual intake air pressure and the model parameter.

[0065] S103: Determine a second charging efficiency according to the exhaust gas recirculation model mass and the fresh intake air mass.

[0066] The fresh intake air amount may be detected by an air flow meter.

[0067] S104: Calculate a difference between the first charging efficiency and the second charging efficiency, and determine whether an exhaust gas recirculation system is faulty according to the difference.

[0068] In the embodiment of the present disclosure, the first charging efficiency calculated by using the actual pressure entering the cylinder does not change significantly when the exhaust gas recirculation system fails, while the second charging efficiency calculated based on the fresh intake air mass and the exhaust gas recirculation model mass changes significantly. Therefore, the first charging efficiency and the second charging efficiency are compared to determine whether the exhaust gas recirculation system is faulty. Using the charging efficiency as the basis for judgment can more accurately distinguish between faulty parts and normal parts, thereby avoiding false alarms or missed alarms.

[0069] In some optional embodiments, determining the actual intake pressure according to the current operating condition of the engine includes:

[0070] Determine the total intake pressure via a pressure sensor;

[0071] According to the current working condition of the engine, a pre-calibrated MAP is searched to determine the sum of the intake cylinder residual exhaust gas pressure and the gas return pressure corresponding to the current working condition;

[0072] The actual intake pressure is determined as the total intake pressure minus the sum of the intake cylinder residual exhaust gas pressure and the gas return pressure.

[0073] Specifically, the actual intake pressure can be calculated according to the formula P 实际 =(P 总 -P 残余+回流 ) is calculated, where P 实际 Indicates the actual intake pressure, P 总 Indicates the total intake pressure, P 残余+回流represents the sum of the residual exhaust gas pressure in the intake cylinder and the gas return pressure. In other words, the first charging efficiency η vol1 According to the formula η vol1 =(P 总 -P 残余+回流 )*FAC calculated.

[0074] By adopting this solution, the actual intake pressure which is difficult to measure directly can be calculated based on the pressure detected by the sensor and the sum of the intake cylinder residual exhaust gas pressure and the gas reflux pressure obtained by querying the pre-calibrated MAP according to the current working conditions.

[0075] In some optional embodiments, determining the second charging efficiency according to the current operating condition, the exhaust gas recirculation model mass and the fresh intake air mass includes:

[0076] determining the exhaust gas recirculation model mass according to an upstream pressure and a downstream pressure of the exhaust gas recirculation valve and an effective cross-sectional area of ​​the exhaust gas recirculation valve;

[0077] Determining an actual intake air volume according to an ideal gas equation, the exhaust gas recirculation model mass, and the fresh intake air mass;

[0078] Determining a standard intake volume according to the total intake pressure, the speed corresponding to the current working condition, and the cylinder volume;

[0079] The second charging efficiency is obtained by dividing the actual intake volume by the standard intake volume.

[0080] Specifically, the exhaust gas recirculation model mass m EGR It can be determined according to the following formula:

[0081]

[0082] Among them, A E represents the effective cross-sectional area of ​​the exhaust gas recirculation valve, P up represents the upstream pressure of the exhaust gas recirculation valve, which can be calculated based on the pre-turbine pressure, P dn represents the downstream pressure of the exhaust gas recirculation valve, which can be calculated according to the intake pressure.

[0083] The second charging efficiency η vol2 It can be calculated according to the following formula:

[0084]

[0085] Among them, due to V 实际It is the sum of the volume of the exhaust gas recirculation system and the fresh intake volume. According to the ideal gas equation PV = mRT, V can be determined 实际 =(m ERG *T EGR )+(m HFM *T 21 ), m HFM represents the fresh air mass, T EGR Indicates the intake air temperature after exhaust gas recirculation cooling, T 21 Indicates the intake air temperature after intercooling, V cyl Indicates cylinder capacity, N eng Indicates the speed corresponding to the current operating condition.

[0086] In some further optional embodiments, determining whether the exhaust gas recirculation system is faulty according to the difference comprises:

[0087] When the difference is greater than a first preset threshold, determining that a positive deviation fault exists in the exhaust gas recirculation system;

[0088] When the difference is less than a second preset threshold, determining that a negative deviation fault exists in the exhaust gas recirculation system;

[0089] The first preset threshold is greater than the second preset threshold.

[0090] The first preset threshold and the second preset threshold may be calibrated according to a dividing line that clearly distinguishes normal parts from faulty parts in actual tests.

[0091] The positive deviation fault indicates that the exhaust gas recirculation system is over-controlled, so that the amount of exhaust gas entering the cylinder is too high, and the charging efficiency is too large, while the negative deviation fault is the opposite. By adopting this solution, by calculating the difference between the first charging efficiency and the second charging efficiency, and by comparing the deviation value with the calibration value, it is determined whether the exhaust gas recirculation system has a positive deviation fault or a negative deviation fault.

[0092] Further, when the difference is greater than a first preset threshold, determining that a positive deviation fault exists in the exhaust gas recirculation system includes:

[0093] When the accumulated time duration during which the difference is greater than the first preset threshold exceeds a first preset time duration, determining that a positive deviation fault exists in the exhaust gas recirculation system;

[0094] When the difference is less than a second preset threshold, determining that a negative deviation fault exists in the exhaust gas recirculation system includes:

[0095] When the accumulated time duration during which the difference is less than the second preset threshold value exceeds the second preset time duration, it is determined that a negative deviation fault exists in the exhaust gas recirculation system.

[0096] For example, the first preset time length may be 5 seconds and the second preset time length may be 6 seconds. The first preset time length may be equal to the second preset time length. For example, the first preset time length and the second preset time length may both be 5 seconds.

[0097] By adopting this solution, by accumulating the duration of the fault, it is determined that the vehicle's exhaust gas recirculation system has a fault when the accumulated duration exceeds the preset duration. This can avoid false alarms caused by calculation errors or other faults, making the fault determination more accurate.

[0098] In some optional implementations, the method further includes:

[0099] Determine whether a preset condition is met according to the current working condition of the vehicle, wherein the preset condition includes:

[0100] The engine speed of the vehicle is within a preset speed range;

[0101] The fuel injection amount of the vehicle is within a preset fuel injection amount range;

[0102] The exhaust gas recirculation system is in a closed-loop control state;

[0103] The opening of the exhaust gas recirculation valve is within a preset opening range;

[0104] The querying of MAP to determine the calibrated charging efficiency according to the engine speed and the fuel injection amount includes:

[0105] When it is determined that the current operating condition of the vehicle meets the preset condition, the calibrated charging efficiency is determined by querying MAP according to the engine speed and the fuel injection amount.

[0106] Among them, the range of the preset speed range and the preset fuel injection amount range can be calibrated according to the vehicle operation area, which is used to eliminate the area where the charging efficiency is inaccurately calculated. In some vehicle tests, it is found that the preset speed range is generally set between 1000-2000 rpm, for example, the preset speed range can be 1500-1800 rpm, and the preset fuel injection amount range is generally set at 0-400 mg / hub (milligrams per stroke), for example, it can be 200-300 mg / hub. The preset opening range can be, for example, greater than 0% and less than 100%, for example, it can also be greater than 0% and less than 80%, and the present disclosure does not limit this.

[0107] By adopting this scheme, when the vehicle's operating conditions meet the preset conditions, the above scheme can be used to determine whether there is a fault in the exhaust gas recirculation system, avoiding missed reports and false alarms. This can not only reduce the amount of calculation of the electronic controller, but also determine whether there is a fault under these operating conditions where faults are prone to occur, making the judgment result more accurate.

[0108] In addition, it is worth noting that the above method is preferably applied to light diesel vehicles. Since the calculation process of determining whether the exhaust gas recirculation system is faulty by the method provided by the embodiment of the present disclosure is more complicated than that of the solution in the related art, therefore, in the case where the related art can already accurately determine whether the exhaust gas recirculation system of a heavy vehicle is faulty, although the method provided by the embodiment of the present disclosure can be used, it may increase the load of the vehicle's processor.

[0109] In order to enable those skilled in the art to better understand the solutions provided by the embodiments of the present disclosure, the present disclosure also provides Figure 2 , another flow chart of an exhaust gas recirculation system fault detection method, such as Figure 2 As shown, the method comprises the steps of:

[0110] S201. Determine whether the current engine operating condition meets a preset condition.

[0111] The preset conditions may include:

[0112] The vehicle's engine speed is greater than or equal to 1000 rpm and less than or equal to 1800 rpm;

[0113] The fuel injection volume of the vehicle is greater than or equal to 100mg / hub and less than or equal to 300mg / hub;

[0114] The exhaust gas recirculation system is in closed-loop control;

[0115] The opening of the exhaust gas recirculation valve is greater than 0% and less than 100%;

[0116] When the preset conditions are met, step S202 and subsequent steps are executed.

[0117] S202, determine the total intake pressure P through the pressure sensor 总 , the fresh air mass m is determined by the air flow meter HFM .

[0118] S203, according to the formula η vol1 =(P 总 -P 残余+回流 )*FAC calculates the first charging efficiency.

[0119] S204, according to the formula The exhaust gas recirculation model mass is calculated.

[0120] S205, according to the formula The second charging efficiency is calculated.

[0121] S206: Calculate the difference between the first charging efficiency and the second charging efficiency.

[0122] S207: Determine whether the difference is greater than a first preset threshold.

[0123] When it is determined that the difference is greater than the first preset threshold, step S209 is executed.

[0124] S208: Determine whether the difference is less than a second preset threshold.

[0125] When it is determined that the difference is less than the second preset threshold, step S210 is executed.

[0126] S209: Determine whether the cumulative time duration during which the difference is greater than the first preset threshold exceeds 5 seconds.

[0127] When it is determined that the accumulated time is greater than 5 seconds, step S211 and step S213 are executed.

[0128] S210: Determine whether the cumulative time length during which the difference is less than the second preset threshold exceeds 5 seconds.

[0129] When it is determined that the accumulated time is greater than 5 seconds, step S212 and step S213 are executed.

[0130] S211. Determine that the exhaust gas recirculation system has a positive deviation fault.

[0131] S212. Determine that the exhaust gas recirculation system has a negative deviation fault.

[0132] S213: Perform corresponding fault processing and activate the fault light.

[0133] In the disclosed embodiment, the calibrated charging efficiency is obtained by querying the MAP, and the estimated charging efficiency is calculated. The calibrated charging efficiency and the estimated charging efficiency are compared to determine whether the exhaust gas recirculation system is faulty. Using the charging efficiency as the basis for judgment can more accurately and clearly distinguish between faulty parts and normal parts, thereby avoiding false alarms or missed alarms.

[0134] Based on the same inventive concept, Figure 3 is a block diagram of an exhaust gas recirculation system fault detection device 30 according to an exemplary embodiment. Figure 3 As shown, the device 30 comprises:

[0135] A first determination module 31, used to determine the actual intake air pressure according to the current working condition of the engine;

[0136] a second determination module 32, configured to determine a first charging efficiency according to the actual intake air pressure and a model parameter, wherein the model parameter is determined according to the volume of the cylinder when the valve is closed, a standard intake air temperature, an actual intake air temperature, a standard atmospheric pressure, and the engine displacement;

[0137] a third determination module 33, configured to determine a second charging efficiency according to the exhaust gas recirculation model mass and the fresh intake air mass;

[0138] The fourth determination module 34 is configured to calculate a difference between the first charging efficiency and the second charging efficiency, and determine whether the exhaust gas recirculation system is faulty according to the difference.

[0139] Optionally, the first determining module 31 is specifically configured to:

[0140] Determine the total intake pressure via a pressure sensor;

[0141] According to the current working condition of the engine, a pre-calibrated MAP is searched to determine the sum of the intake cylinder residual exhaust gas pressure and the gas return pressure corresponding to the current working condition;

[0142] The actual pressure entering the cylinder is determined as the total intake pressure minus the sum of the residual exhaust gas pressure in the intake cylinder and the gas return pressure.

[0143] Optionally, the third determining module 33 is specifically configured to:

[0144] determining the exhaust gas recirculation model mass according to an upstream pressure and a downstream pressure of the exhaust gas recirculation valve and an effective cross-sectional area of ​​the exhaust gas recirculation valve;

[0145] Determining an actual intake air volume according to an ideal gas equation, the exhaust gas recirculation model mass, and the fresh intake air mass;

[0146] Determining a standard intake volume according to the total intake pressure, the speed corresponding to the current working condition, and the cylinder volume;

[0147] The second charging efficiency is obtained by dividing the actual intake volume by the standard intake volume.

[0148] Optionally, the fourth determining module 34 includes:

[0149] a first determination submodule, configured to determine that a positive deviation fault exists in the exhaust gas recirculation system when the difference is greater than a first preset threshold;

[0150] a second determination submodule, configured to determine that a negative deviation fault exists in the exhaust gas recirculation system when the difference is less than a second preset threshold;

[0151] The first preset threshold is greater than the second preset threshold.

[0152] Optionally, the first determining submodule is further configured to:

[0153] When the accumulated time duration during which the difference is greater than the first preset threshold exceeds a first preset time duration, determining that a positive deviation fault exists in the exhaust gas recirculation system;

[0154] The second determining submodule is further specifically used for:

[0155] When the accumulated time duration during which the difference is less than the second preset threshold value exceeds the second preset time duration, it is determined that a negative deviation fault exists in the exhaust gas recirculation system.

[0156] Optionally, the device 30 comprises:

[0157] The third determination module is used to determine whether a preset condition is met according to the current working condition of the vehicle, and the preset condition includes:

[0158] The engine speed of the vehicle is within a preset speed range;

[0159] The fuel injection amount of the vehicle is within a preset fuel injection amount range;

[0160] The exhaust gas recirculation system is in a closed-loop control state;

[0161] The opening of the exhaust gas recirculation valve is within a preset opening range;

[0162] The first determining module 31 is specifically used for:

[0163] When it is determined that the current operating condition of the vehicle satisfies the preset condition, the actual intake air pressure is determined according to the current operating condition of the engine.

[0164] Regarding the device in the above embodiment, the specific manner in which each module performs operations has been described in detail in the embodiment of the method, and will not be elaborated here.

[0165] Figure 4 FIG. 4 is a block diagram of an electronic device 400 according to an exemplary embodiment. Figure 4 As shown, the electronic device 400 may include: a processor 401 and a memory 402. The electronic device 400 may also include one or more of a multimedia component 403, an input / output (I / O) interface 404, and a communication component 405.

[0166] The processor 401 is used to control the overall operation of the electronic device 400 to complete all or part of the steps in the above-mentioned exhaust gas recirculation system fault detection method. The memory 402 is used to store various types of data to support the operation of the electronic device 400, and these data may include, for example, instructions for any application or method operated on the electronic device 400, and application-related data, such as a pre-calibrated MAP, preset thresholds corresponding to multiple parameters, and the cumulative duration of the occurrence of a charging efficiency deviation fault. The memory 402 can be implemented by any type of volatile or non-volatile storage device or a combination thereof, such as static random access memory (SRAM), electrically erasable programmable read-only memory (EEPROM), erasable programmable read-only memory (EPROM), programmable read-only memory (PROM), read-only memory (ROM), magnetic memory, flash memory, disk or optical disk. The multimedia component 403 may include a screen and an audio component. The screen may be, for example, a touch screen, and the audio component is used to output and / or input audio signals. For example, the audio component may include a microphone for receiving external audio signals. The received audio signal may be further stored in the memory 402 or sent via the communication component 405. The audio component also includes at least one speaker for outputting audio signals. The I / O interface 404 provides an interface between the processor 401 and other interface modules, and the above-mentioned other interface modules can be a keyboard, a mouse, buttons, etc. These buttons can be virtual buttons or physical buttons. The communication component 405 is used for wired or wireless communication between the electronic device 400 and other devices. Wireless communication, such as Wi-Fi, Bluetooth, Near Field Communication (NFC), 2G, 3G, 4G, NB-IOT, eMTC, or other 5G, etc., or a combination of one or more of them, is not limited here. Therefore, the corresponding communication component 405 may include: Wi-Fi module, Bluetooth module, NFC module, etc.

[0167] In an exemplary embodiment, the electronic device 400 can be implemented by one or more application specific integrated circuits (ASIC), digital signal processors (DSP), digital signal processing devices (DSPD), programmable logic devices (PLD), field programmable gate arrays (FPGA), controllers, microcontrollers, microprocessors or other electronic components to execute the above-mentioned exhaust gas recirculation system fault detection method.

[0168] In another exemplary embodiment, a computer-readable storage medium including program instructions is also provided, and when the program instructions are executed by a processor, the steps of the above-mentioned exhaust gas recirculation system fault detection method are implemented. For example, the computer-readable storage medium can be the above-mentioned memory 402 including program instructions, and the above-mentioned program instructions can be executed by the processor 401 of the electronic device 400 to complete the above-mentioned exhaust gas recirculation system fault detection method.

[0169] In another exemplary embodiment, a computer program product is also provided. The computer program product includes a computer program executable by a programmable device, and the computer program has a code portion for executing the above exhaust gas recirculation system fault detection method when executed by the programmable device.

[0170] Figure 5 is a block diagram of a vehicle 50 according to an exemplary embodiment. Figure 5 As shown, the vehicle 50 includes an exhaust gas recirculation system 51 and an exhaust gas recirculation system fault detection device 30 connected to the exhaust gas recirculation system 51. The exhaust gas recirculation system fault detection device 30 can be used to execute the steps of the exhaust gas recirculation system fault detection method. Those skilled in the art should know that in a specific implementation, the vehicle 50 also includes other components. Figure 5 Only parts related to the embodiments of the present disclosure are shown, and other necessary vehicle components are not shown one by one.

[0171] The preferred embodiments of the present disclosure are described in detail above in conjunction with the accompanying drawings; however, the present disclosure is not limited to the specific details in the above embodiments. Within the technical concept of the present disclosure, a variety of simple modifications can be made to the technical solution of the present disclosure, and these simple modifications all fall within the protection scope of the present disclosure.

[0172] It should also be noted that the various specific technical features described in the above specific embodiments can be combined in any suitable manner without contradiction. In order to avoid unnecessary repetition, the present disclosure will not further describe various possible combinations.

[0173] In addition, various embodiments of the present disclosure may be arbitrarily combined, and as long as they do not violate the concept of the present disclosure, they should also be regarded as the contents disclosed by the present disclosure.

Claims

1. A method for detecting faults in an exhaust gas recirculation system, characterized in that: The method comprises: Determine the actual intake air pressure according to the current working condition of the engine; Determining a first charging efficiency according to the actual intake air pressure and a model parameter, wherein the model parameter is determined according to a volume of a cylinder when a valve is closed, a standard intake air temperature, an actual intake air temperature, a standard atmospheric pressure, and an engine displacement of the engine; determining a second charging efficiency according to the exhaust gas recirculation model mass and the fresh intake air mass; calculating a difference between the first charging efficiency and the second charging efficiency, and determining whether an exhaust gas recirculation system is faulty according to the difference; The difference is used to compare with the calibration value to determine whether the exhaust gas recirculation system has a positive deviation fault or a negative deviation fault.

2. The method according to claim 1, characterized in that: Determining the actual intake air pressure according to the current working condition of the engine includes: Determine the total intake pressure via a pressure sensor; According to the current working condition of the engine, a pre-calibrated MAP is searched to determine the sum of the intake cylinder residual exhaust gas pressure and the gas return pressure corresponding to the current working condition; The actual pressure entering the cylinder is determined as the total intake pressure minus the sum of the residual exhaust gas pressure in the intake cylinder and the gas return pressure.

3. The method according to claim 2, characterized in that Determining the second charging efficiency according to the current operating condition, the exhaust gas recirculation model mass, and the fresh intake air mass includes: determining the exhaust gas recirculation model mass according to an upstream pressure and a downstream pressure of the exhaust gas recirculation valve and an effective cross-sectional area of ​​the exhaust gas recirculation valve; Determining an actual intake air volume according to an ideal gas equation, the exhaust gas recirculation model mass, and the fresh intake air mass; Determining a standard intake volume according to the total intake pressure, the speed corresponding to the current working condition, and the cylinder volume; The second charging efficiency is obtained by dividing the actual intake volume by the standard intake volume.

4. The method according to claim 1, characterized in that: The determining the first charging efficiency according to the actual intake air pressure and the model parameters includes: determining a first product of a volume of the cylinder when the valve is closed and the standard intake air temperature; Dividing the first product by a second product of the actual intake air temperature, the standard atmospheric pressure, and the engine displacement to obtain a model parameter; The first charging efficiency is determined as a product of the model parameter and the actual intake pressure.

5. The method according to claim 1, characterized in that Determining whether the exhaust gas recirculation system is faulty according to the difference includes: When the difference is greater than a first preset threshold, determining that a positive deviation fault exists in the exhaust gas recirculation system; When the difference is less than a second preset threshold, determining that a negative deviation fault exists in the exhaust gas recirculation system; The first preset threshold is greater than the second preset threshold.

6. The method according to claim 5, characterized in that When the difference is greater than a first preset threshold, determining that a positive deviation fault exists in the exhaust gas recirculation system includes: When the accumulated time duration during which the difference is greater than the first preset threshold exceeds a first preset time duration, determining that a positive deviation fault exists in the exhaust gas recirculation system; When the difference is less than a second preset threshold, determining that a negative deviation fault exists in the exhaust gas recirculation system includes: When the accumulated time duration during which the difference is less than the second preset threshold value exceeds the second preset time duration, it is determined that a negative deviation fault exists in the exhaust gas recirculation system.

7. The method according to any one of claims 1 to 6, characterized in that: The method further comprises: Determine whether a preset condition is met according to the current working condition of the vehicle, wherein the preset condition includes: The engine speed of the vehicle is within a preset speed range; The fuel injection amount of the vehicle is within a preset fuel injection amount range; The exhaust gas recirculation system is in a closed-loop control state; The opening of the exhaust gas recirculation valve is within a preset opening range; Determining the actual intake air pressure according to the current working condition of the engine includes: When it is determined that the current operating condition of the vehicle satisfies the preset condition, the actual intake air pressure is determined according to the current operating condition of the engine.

8. An exhaust gas recirculation system fault detection device, characterized in that: The device comprises: A first determination module, used to determine an actual intake air pressure according to a current operating condition of the engine; a second determination module, configured to determine a first charging efficiency according to the actual intake air pressure and a model parameter, wherein the model parameter is determined according to a volume of a cylinder when a valve is closed, a standard intake air temperature, an actual intake air temperature, a standard atmospheric pressure, and an engine displacement of the engine; a third determination module, configured to determine a second charging efficiency according to the exhaust gas recirculation model mass and the fresh intake air mass; a fourth determination module, configured to calculate a difference between the first charging efficiency and the second charging efficiency, and determine whether an exhaust gas recirculation system is faulty according to the difference; The difference is used to compare with the calibration value to determine whether the exhaust gas recirculation system has a positive deviation fault or a negative deviation fault.

9. A non-transitory computer-readable storage medium having a computer program stored thereon, characterized in that: When the program is executed by a processor, the steps of the method described in any one of claims 1 to 7 are implemented.

10. A vehicle, characterized in that: The vehicle comprises an exhaust gas recirculation system, and an exhaust gas recirculation system fault detection device connected to the exhaust gas recirculation system, wherein the exhaust gas recirculation system fault detection device is used to execute the method according to any one of claims 1-7.

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