Nitrogen-oxygen sensor fault diagnosis method and device, electronic equipment and medium

Abstract

The invention relates to a fault diagnosis method and device for a nitrogen-oxygen sensor, electronic equipment and a medium, and belongs to the technical field of automobiles, and the method comprises the following steps: determining that a target nitrogen-oxygen sensor passes through a dew point, determining that the oxygen concentration of the target nitrogen-oxygen sensor is enabled, determining that an engine is in a normal combustion mode, and determining that the engine is in a normal combustion mode; under the condition that it is determined that the exhaust flow of the engine is larger than a first threshold value, the conversion time of the target nitrogen-oxygen sensor from the oxygen-poor mode to the oxygen-rich mode is obtained, and the occurrence frequency of the target nitrogen-oxygen sensor from the oxygen-poor mode to the oxygen-rich mode is obtained; and based on the conversion time and the number of times, determining whether the target nitrogen-oxygen sensor fails or not. According to the method, the working condition suitable for sensor diagnosis is defined, and after the engine enters the working condition, the fault diagnosis of the nitrogen-oxygen sensor is carried out according to the minimum conversion time of the engine from the oxygen-poor mode to the oxygen-rich mode, so that the fault diagnosis precision of the nitrogen-oxygen sensor is improved.

Description

Technical Field

[0001] The present invention relates to the field of vehicle technology, and in particular to a nitrogen oxygen sensor fault diagnosis method, device, electronic equipment and medium. Background Art

[0002] NOx sensors play a vital role in the exhaust treatment systems of modern vehicles. As an important part of the vehicle's emission control system, they help ensure that the engine runs efficiently while reducing harmful emissions.

[0003] In the diesel engine aftertreatment system, NOx sensors are mainly divided into two types: upstream sensors (upstream oxygen sensors) and downstream sensors (downstream oxygen sensors). The upstream sensor is located in the engine intake system and is responsible for monitoring the oxygen content in the air entering the engine to ensure the correct ratio of fuel to air. The downstream sensor is located in the exhaust system and monitors the exhaust gas after combustion, especially the emission of nitrogen oxides (NOx).

[0004] In the prior art, nitrogen oxide sensor fault diagnosis is performed by comparing model values ​​with sensor measurement values, and the model values ​​are calculated based on fuel and intake air volume, resulting in the fault diagnosis accuracy being affected by other failure forms such as fuel or intake air volume, causing misdiagnosis. Summary of the invention

[0005] In view of this, it is necessary to provide a nitrogen oxygen sensor fault diagnosis method, device, electronic device and medium to solve the problem of low accuracy caused by the prior art of performing sensor fault diagnosis by comparing model values ​​with sensor measurement values.

[0006] In order to solve the above problems, the present invention provides a nitrogen oxygen sensor fault diagnosis method, comprising: When it is determined that the target nitrogen oxide sensor exceeds the dew point, and the oxygen concentration of the target nitrogen oxide sensor is enabled, and the engine is determined to be in the normal combustion mode, and the engine exhaust flow rate is determined to be greater than a first threshold, obtaining the switching time of the target nitrogen oxide sensor from the lean oxygen mode to the rich oxygen mode, and obtaining the number of times the target nitrogen oxide sensor switches from the lean oxygen mode to the rich oxygen mode; Based on the switching time and the number of times, it is determined whether the target nitrogen oxide sensor is malfunctioning.

[0007] In a possible implementation, obtaining the switching time of the target nitrogen oxide sensor from the lean oxygen mode to the rich oxygen mode includes: Get the minimum switching time of the target NOx sensor from lean mode to rich mode.

[0008] In a possible implementation, determining whether the target nitrogen oxide sensor is faulty based on the conversion time and the number of times includes: In a case where it is determined that the conversion time is greater than a second threshold and the number of times is greater than a third threshold, it is determined that the target nitrogen oxygen sensor is faulty.

[0009] In a possible implementation, when it is determined that the conversion time is less than a second threshold and the number of times is greater than a third threshold, it is determined that the target nitrogen oxygen sensor has no fault.

[0010] In a possible implementation, determining a target nitrogen oxide sensor dew point includes: Obtain the working environment temperature and dew point temperature of the target NOx sensor; A target nitrogen oxide sensor dew point is determined based on the operating environment temperature and the dew point temperature.

[0011] In a possible implementation, determining that the target nitrogen oxide sensor oxygen concentration is enabled includes: The oxygen concentration value of the target nitrogen oxygen sensor is obtained, and the target nitrogen oxygen sensor oxygen concentration enable is determined based on the oxygen concentration value.

[0012] In a possible implementation, the normal combustion mode includes: One or more of the NOx control mode and the exhaust temperature management mode.

[0013] On the other hand, the present invention also provides a nitrogen oxygen sensor fault diagnosis device, comprising: A data acquisition module, for acquiring a switching time of the target nitrogen oxide sensor from a lean oxygen mode to an oxygen rich mode, and acquiring a number of times the target nitrogen oxide sensor switches from the lean oxygen mode to the oxygen rich mode, when determining that the target nitrogen oxide sensor exceeds a dew point, determining that the oxygen concentration of the target nitrogen oxide sensor is enabled, determining that the engine is in a normal combustion mode, and determining that the engine exhaust flow rate is greater than a first threshold; The fault judgment module is used to determine whether the target nitrogen oxide sensor is faulty based on the conversion time and the number of times.

[0014] On the other hand, the present invention also provides an electronic device, including a memory and a processor, wherein: The memory is used to store programs; The processor is coupled to the memory and is used to execute the program stored in the memory to implement the steps in a nitrogen oxygen sensor fault diagnosis method described in any one of the above implementations.

[0015] On the other hand, the present invention also provides a computer-readable storage medium for storing computer-readable programs or instructions, which, when executed by a processor, can implement the steps of a nitrogen oxygen sensor fault diagnosis method described in any of the above-mentioned implementation methods.

[0016] The beneficial effects of the present invention are as follows: the present invention provides a method for diagnosing a nitrogen oxide sensor fault, which obtains the conversion time of the target nitrogen oxide sensor from the lean oxygen mode to the rich oxygen mode, and the number of times the target nitrogen oxide sensor changes from the lean oxygen mode to the rich oxygen mode, when determining that the target nitrogen oxide sensor is over-dew point, determining that the oxygen concentration of the target nitrogen oxide sensor is enabled, determining that the engine is in the normal combustion mode, and determining that the engine exhaust flow rate is greater than the first threshold value; based on the conversion time and the number of times, determines whether the target nitrogen oxide sensor is faulty. The present invention defines a working condition suitable for sensor diagnosis, and when the engine enters the working condition, performs a nitrogen oxide sensor fault diagnosis based on the minimum conversion time of the engine from the lean oxygen mode to the rich oxygen mode, thereby improving the accuracy of nitrogen oxide sensor fault diagnosis. BRIEF DESCRIPTION OF THE DRAWINGS

[0017] Figure 1 A flowchart of an embodiment of a method for diagnosing a nitrogen oxygen sensor fault provided by the present invention; Figure 2 A schematic flow chart of an embodiment of a nitrogen oxygen sensor fault diagnosis device provided by the present invention; Figure 3 A schematic structural diagram of an embodiment of an electronic device provided by the present invention. DETAILED DESCRIPTION

[0018] The following will be combined with the drawings in the embodiments of the present invention to clearly and completely describe the technical solutions in the embodiments of the present invention. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative work are within the scope of protection of the present invention.

[0019] In the description of the embodiments of the present application, unless otherwise specified, “plurality” means two or more than two.

[0020] The terms "including" and "having" and any variations thereof in the embodiments of the present invention are intended to cover non-exclusive inclusions. For example, a process, method, apparatus, product or equipment comprising a series of steps or modules is not necessarily limited to those steps or modules clearly listed, but may include other steps or modules not clearly listed or inherent to these processes, methods, products or equipment.

[0021] The naming or numbering of the steps in the embodiments of the present invention does not mean that the steps in the method flow must be executed in the time / logical sequence indicated by the naming or numbering. The execution order of the named or numbered process steps can be changed according to the technical purpose to be achieved, as long as the same or similar technical effects can be achieved.

[0022] Reference to an "embodiment" herein means that a particular feature, structure, or characteristic described in conjunction with the embodiment may be included in at least one embodiment of the present invention. The appearance of the phrase in various places in the specification does not necessarily refer to the same embodiment, nor is it an independent or alternative embodiment that is mutually exclusive with other embodiments. It is explicitly and implicitly understood by those skilled in the art that the embodiments described herein may be combined with other embodiments.

[0023] Before presenting the embodiments, the following terms are explained.

[0024] ‌The main functions of ECU (electronic control unit) include receiving input signals from sensors or other devices, storing, calculating, analyzing and processing relevant data and information, outputting execution instructions to realize driving functions, and outputting fault information. ‌ECU receives input signals from sensors and other devices through input interface circuits, and then stores, calculates and analyzes them through microprocessors. The processed data outputs execution instructions through output interface circuits to drive related equipment to work, and can also provide reference voltage to sensors. ‌

[0025] SCR technology (Selective Catalytic Reduction technology) is a technology used to reduce nitrogen oxide (NOx) emissions in flue gas. SCR technology reacts a reducing agent (such as ammonia or urea) with NOx in flue gas under the action of a catalyst to generate harmless nitrogen and water vapor.

[0026] In the diesel vehicle exhaust treatment system, SCR technology uses a catalyst to inject a reducing agent (usually ammonia or urea) to selectively reduce NOx to N2 and H2O in an oxygen-rich environment. There are two types of catalysts: precious metals and non-precious metals, which can effectively convert NOx into harmless nitrogen and water.

[0027] Working principle of nitrogen oxide sensor When the ignition switch is turned on, the NOx sensor will heat up to 100℃ and then wait for the ECU to send a "dew point" temperature signal. The dew point temperature refers to the temperature at which moisture in the exhaust system no longer condenses. It is usually set between 120℃ and 140℃, and the specific value depends on the outlet temperature of the exhaust system. When the nitrogen oxide sensor receives the dew point temperature signal, it will heat itself to a maximum of 800℃ and start normal operation. At this time, the sensor starts to measure nitrogen oxides and send them to the CAN bus. The engine ECU monitors the emission of nitrogen oxides through this information.

[0028] The role of nitrogen oxide sensors in automobile emission control is as follows: Monitor and control the air-fuel mixture ratio of the engine: The NOx sensor can instantly capture the concentration of nitrogen oxides in the exhaust gas and transmit signals to the ECU through a feedback mechanism, helping the ECU to accurately control the air-fuel mixture ratio, promote efficient combustion process, and reduce exhaust emissions.

[0029] Optimize ignition timing: Based on real-time feedback of nitrogen oxide content, the ECU adjusts the ignition advance angle to ensure that the engine runs in the optimal working state, improve fuel utilization and improve emission performance.

[0030] Fault identification and protection mechanism: Once the NOx sensor detects that exhaust emissions exceed the standard or it fails, it will quickly send a warning signal to the ECU to prevent the engine from continuing to run in an unfavorable state and ensure driving safety.

[0031] ‌Constitutes the cornerstone of the emission control system‌: The monitoring and adjustment data provided by the nitrogen oxide sensor provides important input information for other emission control components (such as three-way catalytic converter, particulate filter, etc.), promoting the smooth operation of the entire emission control system‌.

[0032] The present invention provides a nitrogen oxygen sensor fault diagnosis method, device, electronic equipment and medium, which are described below respectively.

[0033] Figure 1 A schematic flow chart of an embodiment of a nitrogen oxygen sensor fault diagnosis method provided by the present invention is shown as follows: Figure 1 As shown, the nitrogen oxygen sensor fault diagnosis method is applied to ECU, including: S101, when it is determined that the target nitrogen oxide sensor exceeds the dew point, and the oxygen concentration of the target nitrogen oxide sensor is enabled, and the engine is determined to be in a normal combustion mode, and the engine exhaust flow rate is determined to be greater than a first threshold, obtaining a switching time of the target nitrogen oxide sensor from a lean oxygen mode to an oxygen rich mode, and obtaining the number of times the target nitrogen oxide sensor switches from the lean oxygen mode to the oxygen rich mode; S102: Determine whether the target nitrogen oxide sensor is faulty based on the conversion time and the number of times.

[0034] Compared with the prior art, the present embodiment provides a method for diagnosing a nitrogen oxide sensor fault, which obtains the conversion time of the target nitrogen oxide sensor from the lean oxygen mode to the rich oxygen mode, and the number of times the target nitrogen oxide sensor changes from the lean oxygen mode to the rich oxygen mode, when determining that the target nitrogen oxide sensor is over the dew point, determining that the oxygen concentration of the target nitrogen oxide sensor is enabled, determining that the engine is in the normal combustion mode, and determining that the engine exhaust flow rate is greater than the first threshold value; based on the conversion time and the number of times, determines whether the target nitrogen oxide sensor is faulty. The present invention defines a working condition suitable for sensor diagnosis, and when the engine enters the working condition, performs a nitrogen oxide sensor fault diagnosis based on the minimum conversion time of the engine from the lean oxygen mode to the rich oxygen mode, thereby improving the accuracy of nitrogen oxide sensor fault diagnosis.

[0035] It should be noted that the present invention is applicable to diesel engines using the SCR technology. It is understandable that the present invention may also be applicable to other types of vehicles that require the use of the SCR technology.

[0036] In a specific embodiment of the present invention, the target nitrogen oxide sensor is a downstream nitrogen oxide sensor, which is located in the exhaust system to monitor the exhaust gas after combustion, especially the emission of nitrogen oxides (NOx). In the embodiment of the present invention, the conversion time of the downstream nitrogen oxide sensor mode change is greater than a preset threshold under special working conditions to determine whether the downstream nitrogen oxide sensor measurement value is reasonable. If it is reasonable, it is determined that the downstream nitrogen oxide sensor is not faulty, and if it is unreasonable, it is determined that the downstream nitrogen oxide sensor is faulty.

[0037] In some embodiments of the present invention, obtaining the switching time of the target nitrogen oxide sensor from the lean oxygen mode to the rich oxygen mode includes: Get the minimum switching time of the target NOx sensor from lean mode to rich mode.

[0038] Specifically, let's first introduce the oxygen-lean mode and oxygen-rich mode. The oxygen-lean mode means that the concentration of oxygen in the exhaust gas reaches a first preset value, at which time the sensor output voltage is low. The oxygen-rich mode means that the concentration of oxygen in the exhaust gas reaches a second preset value, at which time the sensor output voltage is high.

[0039] Because the NOx sensor can accurately measure the oxygen content in the exhaust gas of the car and control the combustion state of the engine in real time, it plays a very important role in reducing vehicle emissions. If the NOx sensor does not work properly, it will lead to poor engine acceleration, increased fuel consumption, and affect emission performance. Therefore, it is necessary to ensure the rationality of the NOx sensor detection value.

[0040] The above introduces the lean mode and the rich mode. The following describes the conversion time in detail. In a driving cycle, that is, from the vehicle power-on to the shutdown process, the target nitrogen oxide sensor detects the process from the lean mode to the rich mode several times. Each process from the lean mode to the rich mode has a conversion time. The minimum conversion time among the conversion times is obtained.

[0041] In some embodiments of the present invention, determining whether the target nitrogen oxide sensor is faulty based on the conversion time and the number of times includes: In a case where it is determined that the conversion time is greater than a second threshold and the number of times is greater than a third threshold, it is determined that the target nitrogen oxygen sensor is faulty.

[0042] In some embodiments of the present invention, when it is determined that the conversion time is less than a second threshold and the number of times is greater than a third threshold, it is determined that the target nitrogen oxygen sensor has no fault.

[0043] It should be noted that the NOx sensor over-dew point means that the operating temperature of the sensor in the exhaust system reaches or exceeds its dew point temperature, causing the sensor to malfunction or be damaged. The dew point temperature refers to the temperature point at which moisture in the exhaust system condenses. If this temperature point is exceeded, moisture will condense into liquid water, which may damage the sensor.

[0044] In some embodiments of the present invention, determining a target nitrogen oxide sensor dew point includes: Obtain the working environment temperature and dew point temperature of the target NOx sensor; A target nitrogen oxide sensor dew point is determined based on the operating environment temperature and the dew point temperature.

[0045] It should be noted that the NOx sensor oxygen concentration enable means that the NOx sensor can achieve more accurate measurement and control by measuring the oxygen concentration when detecting the NOx concentration in the engine exhaust. The NOx sensor determines the NOx content by measuring the concentration difference between oxygen and NOx in the exhaust gas, and transmits this information to the engine control unit (ECU), thereby adjusting the engine's operating state and reducing exhaust emissions.

[0046] In some embodiments of the present invention, determining the target nitrogen oxide sensor oxygen concentration is enabled includes: The oxygen concentration value of the target nitrogen oxygen sensor is obtained, and the target nitrogen oxygen sensor oxygen concentration enable is determined based on the oxygen concentration value, that is, it is determined that the target nitrogen oxygen sensor is in a normal working state.

[0047] It should be noted that the main function of the NOx control mode is to reduce the emission of nitrogen oxides (NOx). Specifically, NOx is formed by the combination of nitrogen and oxygen at high temperatures (above 1370°C). Therefore, reducing the combustion temperature can effectively reduce the generation of NOx. The exhaust gas recirculation (EGR) system is a key technology to achieve this goal. The EGR system introduces part of the exhaust gas discharged by the engine into the intake pipe, mixes it with fresh air and enters the cylinder, and uses the CO2 in the exhaust gas to absorb heat, thereby reducing the combustion temperature and reducing the generation of NOx. However, the control of the EGR system requires a balance. Excessive exhaust gas recirculation will cause poor ignition of the mixture, increase fuel consumption and reduce power. Therefore, the control of the EGR amount needs to minimize the emission of NOx while ensuring the normal operation of the engine. The main goal of the exhaust temperature management mode is to manage the exhaust temperature of the engine and ensure that the engine runs at the optimal operating temperature, thereby improving fuel economy and engine performance. Only when the engine is at the right temperature can it maintain excellent operating conditions, burn more fully and be more efficient. If the engine temperature is too low, it will lead to incomplete fuel combustion, increased friction and increased fuel consumption; if the temperature is too high, it will damage parts and reduce the lubrication effect of the oil. Therefore, exhaust temperature management optimizes the cooling system to ensure that the engine is neither too cold nor too hot and is always in the best condition. Exhaust temperature management not only focuses on thermal management at high temperatures, but also includes the warm-up process at low temperatures to ensure that the engine can operate efficiently under different working conditions.

[0048] In some embodiments of the present invention, the normal combustion mode includes: One or more of the NOx control mode and the exhaust temperature management mode.

[0049] In a specific embodiment of the present invention, the ECU obtains the combustion mode of the engine by acquiring data from a sensor on the cylinder.

[0050] The present invention determines the rationality of the measurement value of the downstream nitrogen oxide sensor, that is, whether the downstream nitrogen oxide sensor has a fault, based on the fact that the response time of the downstream nitrogen oxide sensor mode change is greater than the calibration value under special working conditions, thereby solving the problem of low accuracy caused by comparing the oxygen content measurement value of the downstream nitrogen oxide sensor with the model calculated value in the prior art.

[0051] In order to better implement a nitrogen oxygen sensor fault diagnosis method in an embodiment of the present invention, based on a nitrogen oxygen sensor fault diagnosis method, correspondingly, as Figure 2 As shown, the embodiment of the present invention further provides a nitrogen oxygen sensor fault diagnosis device, a nitrogen oxygen sensor fault diagnosis device 200 includes: The data acquisition module 201 is used to obtain the switching time of the target nitrogen oxide sensor from the lean oxygen mode to the oxygen rich mode, and the number of times the target nitrogen oxide sensor switches from the lean oxygen mode to the oxygen rich mode when it is determined that the target nitrogen oxide sensor exceeds the dew point, determines that the oxygen concentration of the target nitrogen oxide sensor is enabled, determines that the engine is in the normal combustion mode, and determines that the engine exhaust flow rate is greater than a first threshold value; The fault judgment module 202 is used to determine whether the target nitrogen oxide sensor is faulty based on the conversion time and the number of times.

[0052] The nitrogen oxide sensor fault diagnosis device 200 provided in the above embodiment can implement the technical solution described in the above embodiment of the nitrogen oxide sensor fault diagnosis method. The specific implementation principles of the above modules or units can refer to the corresponding contents in the above embodiment of the nitrogen oxide sensor fault diagnosis method, which will not be repeated here.

[0053] like Figure 3 As shown, the present invention also provides an electronic device 300. The electronic device 300 includes a processor 301, a memory 302 and a display 303. Figure 3 Only some components of the electronic device 300 are shown, but it should be understood that it is not required to implement all of the components shown, and more or fewer components may be implemented instead.

[0054] In some embodiments, the processor 301 may be a central processing unit (CPU), a microprocessor or other data processing chip, which is used to run program codes or process data stored in the memory 302, such as a nitrogen oxygen sensor fault diagnosis method in the present invention.

[0055] In some embodiments, the processor 301 may be a single server or a server group. The server group may be centralized or distributed. In some embodiments, the processor 301 may be local or remote. In some embodiments, the processor 301 may be implemented in a cloud platform. In some embodiments, the cloud platform may include a private cloud, a public cloud, a hybrid cloud, a community cloud, a distributed cloud, an internal cloud, a multi-cloud, etc., or any combination thereof.

[0056] In some embodiments, the memory 302 may be an internal storage unit of the electronic device 300, such as a hard disk or memory of the electronic device 300. In other embodiments, the memory 302 may also be an external storage device of the electronic device 300, such as a plug-in hard disk, a smart media card (SMC), a secure digital (SD) card, a flash card, etc., equipped on the electronic device 300.

[0057] Furthermore, the memory 302 may include both an internal storage unit of the electronic device 300 and an external storage device. The memory 302 is used to store application software installed in the electronic device 300 and various data.

[0058] In some embodiments, the display 303 may be an LED display, a liquid crystal display, a touch-sensitive liquid crystal display, an OLED (Organic Light-Emitting Diode) touch device, etc. The display 303 is used to display information on the electronic device 300 and to display a visual user interface. The components 301-303 of the electronic device 300 communicate with each other via a system bus.

[0059] In one embodiment, when the processor 301 executes a nitrogen oxygen sensor fault diagnosis program in the memory 302, the following steps may be implemented: When it is determined that the target nitrogen oxide sensor exceeds the dew point, and the oxygen concentration of the target nitrogen oxide sensor is enabled, and the engine is determined to be in the normal combustion mode, and the engine exhaust flow rate is determined to be greater than a first threshold, obtaining the switching time of the target nitrogen oxide sensor from the lean oxygen mode to the rich oxygen mode, and obtaining the number of times the target nitrogen oxide sensor switches from the lean oxygen mode to the rich oxygen mode; Based on the switching time and the number of times, it is determined whether the target nitrogen oxide sensor is malfunctioning.

[0060] It should be understood that: when the processor 301 executes a nitrogen oxygen sensor fault diagnosis program in the memory 302, in addition to the above functions, other functions can also be implemented. For details, please refer to the description of the corresponding method embodiment above.

[0061] Furthermore, the embodiment of the present invention does not specifically limit the type of the electronic device 300 mentioned, and the electronic device 300 may be a portable electronic device such as a mobile phone, a tablet computer, a personal digital assistant (PDA), a wearable device, a laptop computer, etc. Exemplary embodiments of portable electronic devices include but are not limited to portable electronic devices equipped with IOS, Android, Microsoft or other operating systems. The above-mentioned portable electronic devices may also be other portable electronic devices, such as a laptop computer with a touch-sensitive surface (e.g., a touch panel). It should also be understood that in some other embodiments of the present invention, the electronic device 300 may not be a portable electronic device, but a desktop computer with a touch-sensitive surface (e.g., a touch panel).

[0062] Those skilled in the art will appreciate that all or part of the processes of the above-mentioned embodiments can be implemented by instructing related hardware through a computer program, and the program can be stored in a computer-readable storage medium, wherein the computer-readable storage medium is a disk, an optical disk, a read-only storage memory, or a random access memory, etc.

[0063] The above description is only a preferred specific implementation manner of the present invention, but the protection scope of the present invention is not limited thereto. Any changes or substitutions that can be easily conceived by any technician familiar with the technical field within the technical scope disclosed by the present invention should be covered within the protection scope of the present invention.

Claims

1. A method for diagnosing a nitrogen oxygen sensor fault, characterized in that: include: When it is determined that the target nitrogen oxide sensor exceeds the dew point, and the oxygen concentration of the target nitrogen oxide sensor is enabled, and the engine is determined to be in the normal combustion mode, and the engine exhaust flow rate is determined to be greater than a first threshold, obtaining the switching time of the target nitrogen oxide sensor from the lean oxygen mode to the rich oxygen mode, and obtaining the number of times the target nitrogen oxide sensor switches from the lean oxygen mode to the rich oxygen mode; Based on the switching time and the number of times, it is determined whether the target nitrogen oxide sensor is malfunctioning.

2. The nitrogen oxide sensor fault diagnosis method according to claim 1, characterized in that: Obtain the conversion time of the target NOx sensor from lean mode to rich mode, including: Get the minimum switching time of the target NOx sensor from lean mode to rich mode.

3. The nitrogen oxygen sensor fault diagnosis method according to claim 2, characterized in that: The determining whether the target nitrogen oxide sensor is faulty based on the conversion time and the number of times includes: In a case where it is determined that the conversion time is greater than a second threshold and the number of times is greater than a third threshold, it is determined that the target nitrogen oxygen sensor is faulty.

4. The nitrogen oxygen sensor fault diagnosis method according to claim 1, characterized in that: In a case where it is determined that the conversion time is less than the second threshold and the number of times is greater than a third threshold, it is determined that the target nitrogen oxygen sensor has no fault.

5. The nitrogen oxide sensor fault diagnosis method according to claim 1, characterized in that: Determine the target NOx sensor dew point, including: Obtain the working environment temperature and dew point temperature of the target NOx sensor; A target nitrogen oxide sensor dew point is determined based on the operating environment temperature and the dew point temperature.

6. The nitrogen oxide sensor fault diagnosis method according to claim 1, characterized in that: The step of determining the target nitrogen oxide sensor oxygen concentration enabling includes: The oxygen concentration value of the target nitrogen oxygen sensor is obtained, and the target nitrogen oxygen sensor oxygen concentration enable is determined based on the oxygen concentration value.

7. The nitrogen oxide sensor fault diagnosis method according to claim 1, characterized in that: The normal combustion mode includes: One or more of the NOx control mode and the exhaust temperature management mode.

8. A nitrogen oxygen sensor fault diagnosis device, characterized in that: include: A data acquisition module, for acquiring a switching time of the target nitrogen oxide sensor from a lean oxygen mode to an oxygen rich mode, and acquiring a number of times the target nitrogen oxide sensor switches from the lean oxygen mode to the oxygen rich mode, when determining that the target nitrogen oxide sensor exceeds a dew point, determining that the oxygen concentration of the target nitrogen oxide sensor is enabled, determining that the engine is in a normal combustion mode, and determining that the engine exhaust flow rate is greater than a first threshold; The fault judgment module is used to determine the eligibility of the target nitrogen oxide sensor based on the conversion time and the number of times.

9. An electronic device, characterized in that: comprising a memory and a processor, wherein: The memory is used to store programs; The processor is coupled to the memory and is used to execute the program stored in the memory to implement the steps in the nitrogen oxygen sensor fault diagnosis method described in any one of claims 1 to 7.

10. A computer-readable storage medium, characterized in that: Used to store computer-readable programs or instructions, which, when executed by a processor, can implement the steps of a nitrogen oxygen sensor fault diagnosis method as described in any one of claims 1 to 7 above.

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