CN116718727A - Vehicle nitrogen-oxygen sensor fault diagnosis method, device and computer equipment - Google Patents
Vehicle nitrogen-oxygen sensor fault diagnosis method, device and computer equipment Download PDFInfo
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- CN116718727A CN116718727A CN202310639106.5A CN202310639106A CN116718727A CN 116718727 A CN116718727 A CN 116718727A CN 202310639106 A CN202310639106 A CN 202310639106A CN 116718727 A CN116718727 A CN 116718727A
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- DOTMOQHOJINYBL-UHFFFAOYSA-N molecular nitrogen;molecular oxygen Chemical compound N#N.O=O DOTMOQHOJINYBL-UHFFFAOYSA-N 0.000 title claims abstract description 105
- 238000003745 diagnosis Methods 0.000 title claims abstract description 69
- 238000000034 method Methods 0.000 title claims abstract description 49
- MWUXSHHQAYIFBG-UHFFFAOYSA-N Nitric oxide Chemical compound O=[N] MWUXSHHQAYIFBG-UHFFFAOYSA-N 0.000 claims abstract description 809
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- RYGMFSIKBFXOCR-UHFFFAOYSA-N Copper Chemical compound [Cu] RYGMFSIKBFXOCR-UHFFFAOYSA-N 0.000 description 1
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Classifications
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- G—PHYSICS
- G01—MEASURING; TESTING
- G01N—INVESTIGATING OR ANALYSING MATERIALS BY DETERMINING THEIR CHEMICAL OR PHYSICAL PROPERTIES
- G01N33/00—Investigating or analysing materials by specific methods not covered by groups G01N1/00 - G01N31/00
- G01N33/0004—Gaseous mixtures, e.g. polluted air
- G01N33/0009—General constructional details of gas analysers, e.g. portable test equipment
- G01N33/007—Arrangements to check the analyser
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- F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
- F01—MACHINES OR ENGINES IN GENERAL; ENGINE PLANTS IN GENERAL; STEAM ENGINES
- F01N—GAS-FLOW SILENCERS OR EXHAUST APPARATUS FOR MACHINES OR ENGINES IN GENERAL; GAS-FLOW SILENCERS OR EXHAUST APPARATUS FOR INTERNAL COMBUSTION ENGINES
- F01N11/00—Monitoring or diagnostic devices for exhaust-gas treatment apparatus, e.g. for catalytic activity
-
- F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
- F01—MACHINES OR ENGINES IN GENERAL; ENGINE PLANTS IN GENERAL; STEAM ENGINES
- F01N—GAS-FLOW SILENCERS OR EXHAUST APPARATUS FOR MACHINES OR ENGINES IN GENERAL; GAS-FLOW SILENCERS OR EXHAUST APPARATUS FOR INTERNAL COMBUSTION ENGINES
- F01N3/00—Exhaust or silencing apparatus having means for purifying, rendering innocuous, or otherwise treating exhaust
- F01N3/08—Exhaust or silencing apparatus having means for purifying, rendering innocuous, or otherwise treating exhaust for rendering innocuous
- F01N3/10—Exhaust or silencing apparatus having means for purifying, rendering innocuous, or otherwise treating exhaust for rendering innocuous by thermal or catalytic conversion of noxious components of exhaust
- F01N3/18—Exhaust or silencing apparatus having means for purifying, rendering innocuous, or otherwise treating exhaust for rendering innocuous by thermal or catalytic conversion of noxious components of exhaust characterised by methods of operation; Control
- F01N3/20—Exhaust or silencing apparatus having means for purifying, rendering innocuous, or otherwise treating exhaust for rendering innocuous by thermal or catalytic conversion of noxious components of exhaust characterised by methods of operation; Control specially adapted for catalytic conversion ; Methods of operation or control of catalytic converters
- F01N3/2066—Selective catalytic reduction [SCR]
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- F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
- F01—MACHINES OR ENGINES IN GENERAL; ENGINE PLANTS IN GENERAL; STEAM ENGINES
- F01N—GAS-FLOW SILENCERS OR EXHAUST APPARATUS FOR MACHINES OR ENGINES IN GENERAL; GAS-FLOW SILENCERS OR EXHAUST APPARATUS FOR INTERNAL COMBUSTION ENGINES
- F01N3/00—Exhaust or silencing apparatus having means for purifying, rendering innocuous, or otherwise treating exhaust
- F01N3/08—Exhaust or silencing apparatus having means for purifying, rendering innocuous, or otherwise treating exhaust for rendering innocuous
- F01N3/10—Exhaust or silencing apparatus having means for purifying, rendering innocuous, or otherwise treating exhaust for rendering innocuous by thermal or catalytic conversion of noxious components of exhaust
- F01N3/18—Exhaust or silencing apparatus having means for purifying, rendering innocuous, or otherwise treating exhaust for rendering innocuous by thermal or catalytic conversion of noxious components of exhaust characterised by methods of operation; Control
- F01N3/20—Exhaust or silencing apparatus having means for purifying, rendering innocuous, or otherwise treating exhaust for rendering innocuous by thermal or catalytic conversion of noxious components of exhaust characterised by methods of operation; Control specially adapted for catalytic conversion ; Methods of operation or control of catalytic converters
- F01N3/2066—Selective catalytic reduction [SCR]
- F01N3/208—Control of selective catalytic reduction [SCR], e.g. dosing of reducing agent
-
- G—PHYSICS
- G01—MEASURING; TESTING
- G01N—INVESTIGATING OR ANALYSING MATERIALS BY DETERMINING THEIR CHEMICAL OR PHYSICAL PROPERTIES
- G01N33/00—Investigating or analysing materials by specific methods not covered by groups G01N1/00 - G01N31/00
- G01N33/0004—Gaseous mixtures, e.g. polluted air
- G01N33/0009—General constructional details of gas analysers, e.g. portable test equipment
- G01N33/0027—General constructional details of gas analysers, e.g. portable test equipment concerning the detector
- G01N33/0036—General constructional details of gas analysers, e.g. portable test equipment concerning the detector specially adapted to detect a particular component
- G01N33/0037—NOx
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- Y—GENERAL TAGGING OF NEW TECHNOLOGICAL DEVELOPMENTS; GENERAL TAGGING OF CROSS-SECTIONAL TECHNOLOGIES SPANNING OVER SEVERAL SECTIONS OF THE IPC; TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS
- Y02—TECHNOLOGIES OR APPLICATIONS FOR MITIGATION OR ADAPTATION AGAINST CLIMATE CHANGE
- Y02A—TECHNOLOGIES FOR ADAPTATION TO CLIMATE CHANGE
- Y02A50/00—TECHNOLOGIES FOR ADAPTATION TO CLIMATE CHANGE in human health protection, e.g. against extreme weather
- Y02A50/20—Air quality improvement or preservation, e.g. vehicle emission control or emission reduction by using catalytic converters
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Abstract
The application relates to a vehicle nitrogen-oxygen sensor fault diagnosis method, a vehicle nitrogen-oxygen sensor fault diagnosis device, a vehicle nitrogen-oxygen sensor fault diagnosis computer device, a vehicle nitrogen-oxygen sensor fault diagnosis storage medium and a vehicle nitrogen-oxygen sensor fault diagnosis computer program product. The method comprises the following steps: determining the average conversion efficiency of the SCR system in a preset enabling period, wherein the preset enabling period is positioned in a period when the working condition of the SCR system is in a stable state; acquiring a first nitrogen oxide concentration actual measurement average value of a first nitrogen oxide sensor in a preset enabling period, and acquiring a second nitrogen oxide concentration actual measurement average value of a second nitrogen oxide sensor in the preset enabling period; determining a theoretical average value of the nitrogen oxide concentration of the first nitrogen oxide sensor according to the average conversion efficiency and the actually measured average value of the second nitrogen oxide concentration; and under the condition that the deviation between the measured average value of the first nitrogen oxide concentration and the theoretical average value of the nitrogen oxide concentration exceeds a preset deviation threshold value, determining that the first nitrogen oxide sensor fails. By adopting the method, the fault of the first nitrogen-oxygen sensor can be diagnosed rapidly, reliably and accurately.
Description
Technical Field
The present application relates to the field of vehicle technologies, and in particular, to a vehicle nitrogen-oxygen sensor fault diagnosis method, a device, a computer device, a storage medium, and a computer program product.
Background
With the exacerbation of the global air pollution problem, sustainable travel has become an important topic of today's society. Among them, the vehicle is one of the main factors causing air pollution, so reducing the influence of the vehicle on the environment is an important aspect of sustainable travel.
Taking a diesel vehicle as an example, in order to meet the national sixth emission regulations, nitrogen-oxygen sensors are respectively disposed upstream and downstream of an SCR (Selective Catalytic Reduction ) system. The upstream nitrogen-oxygen sensor is mainly used for measuring the original nitrogen oxide content in the tail gas discharged by the whole vehicle when the tail gas is not treated yet; the downstream nitrogen-oxygen sensor is mainly used for measuring the content of nitrogen oxides in the tail gas discharged to the air after the tail gas is treated and judging whether the discharged tail gas does not reach the standard. However, the current upstream nitrogen-oxygen sensor is prone to failure during use.
In the related art, when the upstream nitroxide sensor is subjected to fault diagnosis, the diagnosis period is long.
Disclosure of Invention
In view of the foregoing, it is desirable to provide a vehicle nitrogen-oxygen sensor fault diagnosis method, apparatus, computer device, computer readable storage medium, and computer program product that are capable of quick response.
In a first aspect, the present application provides a vehicle nitrogen-oxygen sensor fault diagnosis method, the vehicle including an SCR system, and a first nitrogen-oxygen sensor located at an inlet end of the SCR system and a second nitrogen-oxygen sensor located at an outlet end of the SCR system, the method comprising:
determining average conversion efficiency of the SCR system in a preset enabling period, wherein the preset enabling period is positioned in a period when working conditions of the SCR system are in a stable state;
acquiring a first nitrogen oxide concentration actual measurement average value of the first nitrogen oxide sensor in the preset enabling period, and acquiring a second nitrogen oxide concentration actual measurement average value of the second nitrogen oxide sensor in the preset enabling period;
determining a theoretical average value of the nitrogen oxide concentration of the first nitrogen oxide sensor according to the average conversion efficiency and the actually measured average value of the second nitrogen oxide concentration;
and under the condition that the deviation between the measured average value of the first nitrogen oxide concentration and the theoretical average value of the nitrogen oxide concentration exceeds a preset deviation threshold value, judging that the first nitrogen oxide sensor fails.
In one embodiment, the determining the theoretical average value of the nox concentration of the first nox sensor according to the average conversion efficiency and the measured average value of the second nox concentration includes:
Determining the theoretical average value of the nitrogen oxide concentration according to the ratio of the measured average value of the second nitrogen oxide concentration to the residual rate of nitrogen oxide; wherein the sum of the nitrogen oxide residual rate and the average conversion efficiency is 1.
In one embodiment, the determining the average conversion efficiency of the SCR system over a preset enabling period includes:
and determining the average conversion efficiency according to the ratio of the accumulated value of the conversion efficiency of the SCR system in the preset enabling period to the accumulated times.
In one embodiment, the obtaining the measured average value of the first nox concentration of the first nox sensor in the preset enabling period includes:
and determining the first nitrogen oxide concentration actual measurement average value according to the ratio of the accumulation value of the nitrogen oxide concentration actual measurement value of the first nitrogen oxide sensor in the preset enabling period to the accumulation times.
In one embodiment, when the deviation between the measured average value of the first nox concentration and the theoretical average value of the nox concentration exceeds a preset deviation threshold, the method further includes:
And acquiring the average carrier temperature of the SCR system in the preset enabling period, and compensating the preset deviation threshold according to the average conversion efficiency and the average carrier temperature.
In one embodiment, the vehicle nitrogen-oxygen sensor fault diagnosis method further includes:
acquiring working condition information of the SCR system; wherein, the operating mode information includes: environmental information, engine status information, actuator status information, and SCR system information;
judging whether the working condition of the SCR system is in a stable state according to the working condition information, and determining the average conversion efficiency of the SCR system in the preset enabling period under the condition that the working condition of the SCR system is in the stable state.
In a second aspect, the present application also provides a vehicle nitrogen-oxygen sensor fault diagnosis apparatus, the vehicle including an SCR system, and a first nitrogen-oxygen sensor located at an inlet end of the SCR system and a second nitrogen-oxygen sensor located at an outlet end of the SCR system, the apparatus comprising:
the average conversion efficiency determining module is used for determining the average conversion efficiency of the SCR system in a preset enabling period, wherein the preset enabling period is positioned in a period in which the working condition of the SCR system is in a stable state;
The measured average value acquisition module is used for acquiring a first measured average value of the concentration of the nitrogen oxides of the first nitrogen oxide sensor in the preset enabling period and acquiring a second measured average value of the concentration of the nitrogen oxides of the second nitrogen oxide sensor in the preset enabling period;
the theoretical average value determining module is used for determining the theoretical average value of the nitrogen oxide concentration of the first nitrogen oxide sensor according to the average conversion efficiency and the actually measured average value of the second nitrogen oxide concentration;
the fault judging module is used for judging the first nitrogen-oxygen sensor to be faulty under the condition that the deviation between the measured average value of the first nitrogen oxide concentration and the theoretical average value of the nitrogen oxide concentration exceeds a preset deviation threshold value.
In a third aspect, the present application also provides a computer device. The computer device comprises a memory storing a computer program and a processor which when executing the computer program performs the steps of:
determining average conversion efficiency of the SCR system in a preset enabling period, wherein the preset enabling period is positioned in a period when working conditions of the SCR system are in a stable state;
Acquiring a first nitrogen oxide concentration actual measurement average value of the first nitrogen oxide sensor in the preset enabling period, and acquiring a second nitrogen oxide concentration actual measurement average value of the second nitrogen oxide sensor in the preset enabling period;
determining a theoretical average value of the nitrogen oxide concentration of the first nitrogen oxide sensor according to the average conversion efficiency and the actually measured average value of the second nitrogen oxide concentration;
and under the condition that the deviation between the measured average value of the first nitrogen oxide concentration and the theoretical average value of the nitrogen oxide concentration exceeds a preset deviation threshold value, judging that the first nitrogen oxide sensor fails.
In a fourth aspect, the present application also provides a computer-readable storage medium. The computer readable storage medium having stored thereon a computer program which when executed by a processor performs the steps of:
determining average conversion efficiency of the SCR system in a preset enabling period, wherein the preset enabling period is positioned in a period when working conditions of the SCR system are in a stable state;
acquiring a first nitrogen oxide concentration actual measurement average value of the first nitrogen oxide sensor in the preset enabling period, and acquiring a second nitrogen oxide concentration actual measurement average value of the second nitrogen oxide sensor in the preset enabling period;
Determining a theoretical average value of the nitrogen oxide concentration of the first nitrogen oxide sensor according to the average conversion efficiency and the actually measured average value of the second nitrogen oxide concentration;
and under the condition that the deviation between the measured average value of the first nitrogen oxide concentration and the theoretical average value of the nitrogen oxide concentration exceeds a preset deviation threshold value, judging that the first nitrogen oxide sensor fails.
In a fifth aspect, the present application also provides a computer program product. The computer program product comprises a computer program which, when executed by a processor, implements the steps of:
determining average conversion efficiency of the SCR system in a preset enabling period, wherein the preset enabling period is positioned in a period when working conditions of the SCR system are in a stable state;
acquiring a first nitrogen oxide concentration actual measurement average value of the first nitrogen oxide sensor in the preset enabling period, and acquiring a second nitrogen oxide concentration actual measurement average value of the second nitrogen oxide sensor in the preset enabling period;
determining a theoretical average value of the nitrogen oxide concentration of the first nitrogen oxide sensor according to the average conversion efficiency and the actually measured average value of the second nitrogen oxide concentration;
And under the condition that the deviation between the measured average value of the first nitrogen oxide concentration and the theoretical average value of the nitrogen oxide concentration exceeds a preset deviation threshold value, judging that the first nitrogen oxide sensor fails.
The vehicle nitrogen-oxygen sensor fault diagnosis method, the vehicle nitrogen-oxygen sensor fault diagnosis device, the computer equipment, the storage medium and the computer program product are used for determining the theoretical average value of the nitrogen oxide concentration of the first nitrogen-oxygen sensor by utilizing the average conversion efficiency of the SCR system in a preset enabling period and the actual measurement average value of the second nitrogen oxide concentration of the second nitrogen-oxygen sensor in the preset enabling period; and whether the first nitrogen oxide sensor fails or not can be judged by judging whether the deviation between the measured average value of the first nitrogen oxide concentration of the first nitrogen oxide sensor in the preset enabling period and the theoretical average value of the nitrogen oxide concentration exceeds a preset deviation threshold value, so that the diagnosis process is quick, the responsiveness is quick, and meanwhile, the reliability of the SCR system and the reliability of the second nitrogen oxide sensor are high, the determined average conversion efficiency and the obtained measured average value of the second nitrogen oxide concentration are accurate, so that the reliability of the failure diagnosis result of the first nitrogen oxide sensor is high.
Drawings
FIG. 1 is a diagram of an application environment of a vehicle nitrogen-oxygen sensor fault diagnosis method in one embodiment;
FIG. 2 is a flow chart of a method for diagnosing a vehicle NOx sensor fault in one embodiment;
FIG. 3 is a flow chart of a method for diagnosing a vehicle NOx sensor fault in another embodiment;
FIG. 4 is a flow chart of a method for diagnosing a vehicle NOx sensor fault in another embodiment;
FIG. 5 is a block diagram showing a configuration of a vehicle nitrogen-oxygen sensor malfunction diagnosis apparatus in one embodiment.
Detailed Description
The present application will be described in further detail with reference to the drawings and examples, in order to make the objects, technical solutions and advantages of the present application more apparent. It should be understood that the specific embodiments described herein are for purposes of illustration only and are not intended to limit the scope of the application.
The fault diagnosis method for the vehicle nitrogen-oxygen sensor provided by the embodiment of the application can be applied to an application environment shown in fig. 1. As shown in fig. 1, the application environment may include: engine 100, which may be but is not limited to a diesel engine or a gasoline engine, is used to power a vehicle; an intake system 200 for supplying air to cylinders of the engine 100; an exhaust system 300 for discharging exhaust gas in a cylinder of the engine 100, that is, exhaust gas of a vehicle; the aftertreatment system 400 is used for treating the exhaust gas to reduce the content of harmful substances therein, so that the exhaust gas has less pollution to the environment when being discharged into the air.
Further, taking a diesel engine as an example, aftertreatment system 400 may include: SCR system for converting Nitrogen Oxides (NO) in exhaust gas using urea X ) Catalytic reduction to nitrogen (N) 2 ) And water (H) 2 O); the first nitrogen-oxygen sensor 410 is located at the inlet end of the SCR system, and is mainly used for measuring the original nitrogen oxide content in the tail gas; the second nitrogen-oxygen sensor 420 is located at the outlet end of the SCR system, and is mainly used for measuring the content of nitrogen oxides in the exhaust gas when the exhaust gas is discharged to the air after the exhaust gas is catalyzed and reduced by the SCR system. Wherein, depending on the flow direction of the gas stream in the aftertreatment system 400, the first nitrogen-oxygen sensor 410 is located upstream of the SCR system and may be used as an upstream nitrogen-oxygen sensor, and the second nitrogen-oxygen sensor 420 is located downstream of the SCR system and may be used as a downstream nitrogen-oxygen sensor. Further, the SCR system may be provided with a urea supply unit, a carrier, a catalyst, a first temperature sensor 430 at an inlet end of the SCR system, and a second temperature sensor 440 at an outlet end of the SCR system. Wherein the urea supply unit is capable of injecting urea, the carrier is mainly used for providing an adhesion position for a catalyst, and the catalyst can be, but is not limited to, a copper-based catalyst; the first temperature sensor 430 and the second temperature sensor 440 are used for detecting whether the temperature of the SCR system reaches a required temperature, so as to ensure that the catalytic reduction reaction in the SCR system is performed normally.
Further, still taking a diesel engine as an example, aftertreatment system 400 may further include: DOC (Diesel Oxidation Catalyst, oxidation catalyst) system, can be set between the first nitrogen-oxygen sensor 410 and SCR system, in other application scenario, can also be that the first nitrogen-oxygen sensor 410 is set between DOC system and SCR system, DOC system is mainly used for oxidizing Hydrocarbon (HC) in tail gas into H 2 O and carbon dioxide (CO) 2 ) And oxidizing NO to NO 2 The method comprises the steps of carrying out a first treatment on the surface of the A DPF (Diesel Particulate Filter, wall-flow particle catcher) system, which may be disposed at an outlet end of the DOC system, and in other application scenarios, the first nitroxide sensor 410 may be disposed between the DPF system and the SCR system, where the DPF system is mainly used for capturing particles in the exhaust gas; an ASC (Ammonia Slip Catalyst, ammonia oxidation catalyst) system may be disposed between the SCR system and the second NOx sensor 420, primarily for converting excess ammonia (NH) in the exhaust gas 3 ) Conversion to N 2 . Further, DA third temperature sensor 450 at the inlet end of the DOC system may be provided in the OC system, and similarly, a differential pressure sensor 460 may be provided in the DPF system, and a fourth temperature sensor 470 at the inlet end of the DPF system.
In one embodiment, as shown in fig. 2, a method for diagnosing a vehicle nitrogen-oxygen sensor fault is provided, and is described as being applied to the diesel vehicle including the SCR system, the first nitrogen-oxygen sensor 410, and the second nitrogen-oxygen sensor 420 in fig. 1, and includes the following steps 202 to 208.
Step 202, determining average conversion efficiency of the SCR system in a preset enabling period, wherein the preset enabling period is positioned in a period when working conditions of the SCR system are in a stable state.
The running condition of the SCR system at a certain moment is called as the working condition of the SCR system for short. The period of time that the operating condition of the SCR system is in a steady state can be understood as: the working condition information of the working condition of the SCR system is represented, wherein the sizes of various parameters cannot change greatly, but at most, tiny fluctuation exists, the SCR system stably operates, and the catalytic reduction reaction in the SCR system is stably and efficiently carried out for a period of time. For example, during a start-up phase of the SCR system, each parameter in the operating condition information of the SCR system is unstable, a part of the parameters may change greatly, and it may be determined that the operating condition of the SCR system is unstable during the period, while as the start-up phase gradually ends, the catalytic reduction reaction in the SCR system gradually occurs in a large amount, and the SCR system gradually enters a stable operating state until the operating condition of the SCR system is in a stable state and continues for a long period.
The preset enabling period is a smaller period set in a period in which the SCR system operating condition is in a steady state. In the period that the working condition of the SCR system is in a stable state, a plurality of preset enabling periods can be set, and one or more cycles of fault diagnosis can be carried out on the first nitrogen-oxygen sensor by utilizing the preset enabling periods; in the fault diagnosis of one cycle, one preset enabling period corresponds to only one fault diagnosis of the first nitrogen-oxygen sensor.
The conversion efficiency of the SCR system means that the SCR system converts NO in the tail gas X Catalytic reduction to nitrogen N 2 Is not limited to the above-described embodiments. Under the condition that urea is supplied normally and the carrier is normal, the conversion efficiency can be determined by a physical model based on the physical characteristics of the SCR system; wherein, parameters adopted in the physical model comprise parameters in the working condition information.
The fault diagnosis device of the nitrogen-oxygen-nitrogen-oxygen sensor of the computer equipment or the vehicle can be used for determining a plurality of conversion efficiencies of the SCR system by utilizing the physical model in a preset enabling period, and further, the conversion efficiencies are averaged, so that the average conversion efficiency of the SCR system in the preset enabling period is obtained. In this embodiment, the setting of the enabling period is preset in order to make the average conversion efficiency determined based on the physical model more accurate. In other words, in the preset enabling period, the working condition of the SCR system is in a stable state, and parameters in the working condition information of the SCR system are stable, so that the average conversion efficiency determined based on the physical model can more accurately represent the actual conversion efficiency of the SCR system in the preset enabling period.
Step 204, obtaining a first nitrogen oxide concentration actual measurement average value of the first nitrogen oxide sensor in a preset enabling period, and obtaining a second nitrogen oxide concentration actual measurement average value of the second nitrogen oxide sensor in the preset enabling period.
The computer equipment or the vehicle nitrogen-oxygen sensor fault diagnosis device can acquire a plurality of actual measurement values of the nitrogen oxide concentration of the first nitrogen-oxygen sensor in a preset enabling period, and further average the plurality of actual measurement values of the nitrogen oxide, so that an actual measurement average value of the first nitrogen oxide concentration of the first nitrogen-oxygen sensor in the preset enabling period is obtained.
Similarly, the computer equipment or the vehicle nitrogen-oxygen sensor fault diagnosis device can acquire a plurality of actual measurement values of the concentration of the nitrogen oxide of the second nitrogen-oxygen sensor in a preset enabling period, and further average the plurality of actual measurement values of the nitrogen oxide, thereby obtaining an actual measurement average value of the concentration of the second nitrogen oxide of the second nitrogen-oxygen sensor in the preset enabling period.
In this embodiment, during the preset enabling period, the working condition of the SCR system is in a stable state, and the load of the vehicle is usuallyMedium and high load, NO to be measured by the second nitroxide sensor X The content is not too large or too small, so that the obtained actual measurement average value of the concentration of the second nitrogen oxide can accurately reflect the actual measurement value of the concentration of the real nitrogen oxide measured by the second nitrogen oxide sensor in the preset enabling period.
And 206, determining a theoretical average value of the nitrogen oxide concentration of the first nitrogen oxide sensor according to the average conversion efficiency and the actual measured average value of the second nitrogen oxide concentration.
The theoretical average value of the nitrogen oxide concentration of the first nitrogen oxide sensor in the preset enabling period can be calculated by the computer equipment or the vehicle nitrogen oxide sensor fault diagnosis device according to the average conversion efficiency of the SCR system in the preset enabling period and the actual measured average value of the second nitrogen oxide concentration of the second nitrogen oxide sensor in the preset enabling period.
In this embodiment, according to the foregoing, in the preset enabling period, the determined average conversion efficiency is more accurate, and the obtained actual measurement average value of the second nox concentration is more accurate, so that the calculated theoretical average value of the nox concentration of the first nox sensor can be ensured, and the actual value of the nox concentration that should be measured by the first nox sensor in the preset enabling period can be accurately represented.
And step 208, judging that the first nitrogen-oxygen sensor fails under the condition that the deviation between the measured average value of the first nitrogen oxide concentration and the theoretical average value of the nitrogen oxide concentration exceeds a preset deviation threshold value.
The computer equipment or the vehicle nitrogen-oxygen sensor fault diagnosis device can determine the deviation between the measured average value of the first nitrogen oxide concentration of the first nitrogen-oxygen sensor in the preset enabling period and the theoretical average value of the nitrogen oxide concentration of the first nitrogen-oxygen sensor in the preset enabling period, and further judge whether the deviation exceeds a preset deviation threshold value. If not, it means that the measured value of the concentration of the nitrogen oxide measured by the first nitrogen oxide sensor is the same as or substantially similar to the value of the concentration of the nitrogen oxide which should be measured by the first nitrogen oxide sensor, and the first nitrogen oxide sensor has no fault. If the measured value of the nitrogen oxide concentration measured by the first nitrogen oxide sensor is too different from the measured value of the nitrogen oxide concentration measured by the first nitrogen oxide sensor, the measured value of the nitrogen oxide concentration measured by the first nitrogen oxide sensor deviates from the measured value of the nitrogen oxide concentration measured by the first nitrogen oxide sensor by too much, and the first nitrogen oxide sensor has a rationality fault, so that the first nitrogen oxide sensor can be judged to be faulty.
In the vehicle nitrogen-oxygen sensor fault diagnosis method, the preset enabling period is set in a period when the working condition of the SCR system is in a stable state. And in a preset enabling period, all parameters in the working condition information of the SCR system are stable, so that the average conversion efficiency of the SCR system is accurately determined, the actual measurement average value of the concentration of the second nitrogen oxide sensor is accurately obtained, and the accurate theoretical average value of the concentration of the nitrogen oxide of the first nitrogen oxide sensor is calculated according to the average conversion efficiency and the actual measurement average value of the concentration of the second nitrogen oxide. Therefore, whether the first nitrogen oxide sensor fails or not can be accurately judged by judging whether the deviation between the measured average value of the first nitrogen oxide concentration of the first nitrogen oxide sensor and the theoretical average value of the nitrogen oxide concentration of the first nitrogen oxide sensor exceeds a preset deviation threshold value, the diagnosis process is rapid, the responsiveness is rapid, and meanwhile, the reliability of the failure diagnosis result of the first nitrogen oxide sensor is high due to the fact that the reliability of the SCR system and the reliability of the second nitrogen oxide sensor are high.
In one embodiment, determining the average conversion efficiency of the SCR system over a preset enabling period in step 202 includes: and determining the average conversion efficiency according to the ratio of the accumulated value of the conversion efficiency of the SCR system in the preset enabling period to the accumulated times.
The time length of the preset enabling period and the accumulated frequency of the conversion efficiency in the preset enabling period can be set according to actual vehicle types. For example, for heavy vehicles (such as tractors), the length of the preset enabling period is relatively long and the cumulative frequency of conversion efficiency is relatively low, because heavy vehicle conditions are generally relatively stable, while urban vehicles (such as sprinkler trucks) the length of the preset enabling period is relatively short and the cumulative frequency of conversion efficiency is relatively high. The computer equipment or the vehicle nitrogen-oxygen sensor fault diagnosis device can determine the accumulated times of the conversion efficiency in the preset enabling period according to the product of the time length of the preset enabling period and the accumulated frequency of the conversion efficiency, and determine the accumulated value of the conversion efficiency of the SCR system in the preset enabling period as the accumulated total conversion efficiency in the preset enabling period. For example, the average conversion efficiency may be determined according to the following formula:
Wherein eta Flat plate For average conversion efficiency, η m For the conversion efficiency at the mth integration, n is the total integration number in one enabled period.
The method can calculate the accumulated value of the conversion efficiency of the SCR system in the preset enabling period and the accumulated times of the conversion efficiency in the preset enabling period by using the computer equipment or the vehicle nitrogen-oxygen sensor fault diagnosis device, further calculate the average conversion efficiency of the SCR system in the preset enabling period, and therefore the process of determining the average conversion efficiency is quick, and the calculation mode is simple and easy to realize.
In one embodiment, the obtaining the measured average value of the first nox concentration of the first nox sensor in the preset enabling period in step 204 includes: and determining a first nitrogen oxide concentration actual measurement average value according to the ratio of the cumulative value of the nitrogen oxide concentration actual measurement value of the first nitrogen oxide sensor in the preset enabling section to the cumulative frequency.
In the preset enabling period, the accumulated frequency of the measured value of the concentration of the nitrogen oxide measured by the first nitrogen oxide sensor is the same as the accumulated frequency of the conversion efficiency. For example, the measured average value of the first nox concentration may be determined according to the following formula:
Wherein the method comprises the steps of，D1 Flat plate D1 is the measured average value of the concentration of the first nitrogen oxide m And n is the total accumulated times in an enabling period, which is the actual measured value of the concentration of the nitrogen oxide during the mth accumulated time of the first nitrogen oxide sensor.
The method can calculate the accumulated value of the measured value of the nitrogen oxide concentration of the first nitrogen oxide sensor in the preset enabling period according to the formula by using the computer equipment or the vehicle nitrogen oxide sensor fault diagnosis device, further calculate the accumulated times of the measured value of the nitrogen oxide concentration in the preset enabling period, further calculate the measured average value of the first nitrogen oxide concentration, and therefore the process of determining the measured average value of the first nitrogen oxide concentration is quick, and the calculation mode is simple and easy to realize.
In one embodiment, the obtaining the measured average value of the second nox concentration of the second nox sensor in the preset enabling period in step 204 includes: and determining a second nitrogen oxide concentration actual measurement average value according to the ratio of the actual measurement value of the nitrogen oxide concentration of the second nitrogen oxide sensor in the preset enabling section to the accumulation number.
In the preset enabling period, the accumulated frequency of the measured value of the concentration of the nitrogen oxide measured by the second nitrogen oxide sensor is the same as the accumulated frequency of the conversion efficiency. For example, the second nox concentration measured average value may be determined according to the following formula:
Wherein D2 Flat plate Is the measured average value of the concentration of the second nitrogen oxide, D2 m And n is the total accumulated times in an enabling period, which is the actual measured value of the concentration of the nitrogen oxide during the mth accumulated time of the second nitrogen oxide sensor.
The fault diagnosis device of the nitrogen-oxygen sensor of the computer equipment or the vehicle can calculate the accumulated value of the actual measurement value of the nitrogen oxide concentration of the second nitrogen-oxygen sensor in the preset enabling period according to the formula, further calculate the accumulated times of the actual measurement value of the nitrogen oxide concentration in the preset enabling period, further calculate the actual measurement average value of the second nitrogen oxide concentration, and therefore the process of determining the actual measurement average value of the second nitrogen oxide concentration is quick, and the calculation mode is simple and easy to realize.
In one embodiment, determining the theoretical average of nox concentration of the first nox sensor in step 206 based on the average conversion efficiency and the measured average of the second nox concentration includes: determining a theoretical average value of the concentration of the nitrogen oxides according to the ratio of the measured average value of the concentration of the second nitrogen oxides to the residual rate of the nitrogen oxides; wherein the sum of the nitrogen oxide residual rate and the average conversion efficiency is 1.
For example, the theoretical average of the nox concentration of the first nox sensor may be determined according to the following formula:
Wherein D11 Flat plate Is the theoretical average value of the concentration of nitrogen oxides (1-eta) of the first nitrogen-oxygen sensor Flat plate ) Can be understood as the residual amount of nitrogen oxides.
The nitrogen oxide residual quantity can be calculated by the computer equipment or the vehicle nitrogen oxide sensor fault diagnosis device according to the formula, so that the theoretical average value of the nitrogen oxide concentration of the first nitrogen oxide sensor in the preset enabling period is calculated, the process of determining the theoretical average value of the nitrogen oxide concentration is quick, and the calculation mode is simple and easy to realize.
In one embodiment, as shown in FIG. 3, a vehicle nitrogen-oxygen sensor fault diagnosis method includes the following steps 302-310.
Step 302, determining average conversion efficiency of the SCR system in a preset enabling period, where the preset enabling period is located in a period where the working condition of the SCR system is in a stable state.
Step 304, obtaining a first nitrogen oxide concentration actual measurement average value of the first nitrogen oxide sensor in a preset enabling period, and obtaining a second nitrogen oxide concentration actual measurement average value of the second nitrogen oxide sensor in the preset enabling period.
Step 306, determining a theoretical average value of the nitrogen oxide concentration of the first nitrogen oxide sensor according to the average conversion efficiency and the actual measured average value of the second nitrogen oxide concentration.
Step 308, obtaining the average carrier temperature of the SCR system in the preset enabling period, and compensating the preset deviation threshold according to the average conversion efficiency and the average carrier temperature.
The average carrier temperature of the SCR system in the preset enabling period is the average carrier temperature of the SCR system in the preset enabling period. The temperature of the SCR carrier has a larger influence on the stability of the working condition of the SCR system, so that the average carrier temperature of the SCR system in the preset enabling period is considered according to the average conversion efficiency of the SCR system in the preset enabling period, the preset deviation threshold is compensated, corrected or calibrated, and the accuracy of the preset deviation threshold is ensured to be higher under different average conversion efficiencies and/or different average carrier temperatures, so that the fault diagnosis result of the first nitrogen-oxygen sensor is ensured to be more accurate and reliable.
The method for compensating the preset deviation threshold value ensures higher accuracy of the preset deviation threshold value under different average conversion efficiency and/or different average carrier temperature, and the specific compensation modes can be various, and the method for compensating the preset deviation threshold value in the embodiment of the application is not particularly limited, and is exemplified below:
The preset deviation threshold value can be compensated by the computer equipment or the vehicle nitrogen-oxygen sensor fault diagnosis device by utilizing a preset deviation threshold value lookup table. The deviation threshold lookup table includes deviation thresholds corresponding to the average conversion efficiency and the average temperature of the support, and the deviation thresholds corresponding to at least one of the average conversion efficiency and the average temperature of the support may be changed. The computer equipment or the vehicle nitrogen-oxygen sensor fault diagnosis device can find a corresponding deviation threshold value in the deviation threshold value lookup table according to the average conversion efficiency and the average carrier temperature, and can be used as a preset deviation threshold value to realize the correction of the preset deviation threshold value.
The deviation threshold lookup table may be pre-established by the computer device prior to performing the fault diagnosis on the first nitrogen-oxygen sensor. The deviation threshold lookup table can determine a theoretical nitrogen oxide concentration value of the first nitrogen oxide sensor by adopting the conversion efficiency of the SCR system and the actual nitrogen oxide concentration value of the second nitrogen oxide sensor in a preset enabling period under the condition that the first nitrogen oxide sensor and the second nitrogen oxide sensor are determined to be free from faults; determining a deviation value according to the difference value between the measured value of the nitrogen oxide concentration of the first nitrogen oxide sensor and the theoretical value of the nitrogen oxide concentration; and further, according to a plurality of deviation values in a preset enabling period, determining a deviation range (comprising a deviation upper limit value and a deviation lower limit value) corresponding to the average conversion efficiency and the average carrier temperature in the preset enabling period, namely determining a deviation threshold value.
And step 310, judging that the first nitrogen-oxygen sensor fails under the condition that the deviation between the measured average value of the first nitrogen oxide concentration and the theoretical average value of the nitrogen oxide concentration exceeds a preset deviation threshold value. The preset deviation threshold is a deviation threshold corrected in the step 308, that is, the deviation threshold corrected in the step 308 is adopted in the step to determine whether the first nitrogen-oxygen sensor is faulty, so that a fault diagnosis result of the first nitrogen-oxygen sensor is more accurate and reliable.
In one embodiment, as shown in FIG. 4, a vehicle nitrogen-oxygen sensor fault diagnosis method includes the following steps 402-412.
Step 402, acquiring working condition information of an SCR system; wherein, the operating mode information includes: environmental information, engine status information, actuator status information, related sensor operating status information, second NOx sensor status information, and SCR system information.
The working condition information of the SCR system can be obtained by a computer device or a vehicle nitrogen-oxygen sensor fault diagnosis device. The environment information in the working condition information comprises atmospheric temperature and pressure; engine state information includes engine run time, combustion mode, and coolant temperature; the actuator state information includes boost pressure information, EGR valve information, throttle valve state information, and urea nozzle state information; the second nitroxide sensor status information includes: the NOx concentration measured by the second nitrogen-oxygen sensor, the NOx mass flow measured by the second nitrogen-oxygen sensor, and the NOx mass flow measured by the second nitrogen-oxygen sensor after filtering; the SCR system information comprises SCR carrier temperature, NH3 storage amount, SCR inlet end temperature change gradient, urea injection amount and SCR system working mode.
Step 404, judging whether the working condition of the SCR system is in a stable state according to the working condition information, and determining the average conversion efficiency of the SCR system in a preset enabling period under the condition that the working condition of the SCR system is in a stable state.
The fault diagnosis device of the nitrogen-oxygen sensor of the computer equipment or the vehicle can judge whether the working condition of the SCR system is in a stable state according to the working condition information. The fault diagnosis device of the computer equipment or the vehicle nitrogen-oxygen sensor can judge that the working condition of the SCR system is in a stable state under the condition that all parameters in the working condition information respectively reach corresponding thresholds and the sizes of all parameters are not changed greatly but only have tiny fluctuation, or else, the working condition of the SCR system is judged not to enter the stable state. Further, under the condition that the working condition of the SCR system is judged to be in a stable state, the computer equipment or the vehicle nitrogen-oxygen sensor fault diagnosis device can diagnose whether the first nitrogen-oxygen sensor is in fault or not in a preset enabling period.
Step 406, obtaining a measured average value of the first nitrogen oxide concentration of the first nitrogen oxide sensor in a preset enabling period, and obtaining a measured average value of the second nitrogen oxide concentration of the second nitrogen oxide sensor in the preset enabling period.
Step 408, determining a theoretical average value of the nitrogen oxide concentration of the first nitrogen oxide sensor according to the average conversion efficiency and the actual measured average value of the second nitrogen oxide concentration.
In step 410, if the deviation between the measured average value of the first nox concentration and the theoretical average value of the nox concentration exceeds the preset deviation threshold, it is determined that the first nox sensor is malfunctioning.
In the above vehicle nitrogen-oxygen sensor fault diagnosis method, the computer device or the vehicle nitrogen-oxygen sensor fault diagnosis device may acquire working condition information of the SCR system, and perform fault diagnosis on the first nitrogen-oxygen sensor in a preset enabling period when it is determined that the working condition of the SCR system is in a stable state according to the working condition information. In the fault diagnosis stage, the computer equipment or the vehicle nitrogen-oxygen sensor fault diagnosis device can determine the average conversion efficiency of the SCR system in the preset enabling period according to the ratio of the accumulated value of the conversion efficiency of the SCR system in the preset enabling period to the accumulated times; determining a first nitrogen oxide concentration actual measurement average value according to the ratio of the accumulation value of the nitrogen oxide concentration actual measurement value of the first nitrogen oxide sensor in a preset enabling period to the accumulation times; determining a second nitrogen oxide concentration actual measurement average value according to the ratio of the accumulation value of the nitrogen oxide concentration actual measurement value of the second nitrogen oxide sensor in a preset enabling period to the accumulation times; determining a theoretical average value of the nitrogen oxide concentration of the first nitrogen oxide sensor according to the ratio of the measured average value of the second nitrogen oxide concentration to the nitrogen oxide residual rate, wherein the sum of the nitrogen oxide residual rate and the average conversion efficiency is 1; acquiring the average carrier temperature of the SCR system in a preset enabling period, and compensating a preset deviation threshold according to the average conversion efficiency and the average carrier temperature; and whether the deviation between the measured average value of the first nitrogen oxide concentration and the theoretical average value of the nitrogen oxide concentration exceeds the preset deviation threshold value can be judged accurately, and whether the first nitrogen oxide sensor fails or not can be judged accurately.
It should be understood that, although the steps in the flowcharts related to the above embodiments are sequentially shown as indicated by arrows, these steps are not necessarily sequentially performed in the order indicated by the arrows. The steps are not strictly limited to the order of execution unless explicitly recited herein, and the steps may be executed in other orders. Moreover, at least some of the steps in the flowcharts described in the above embodiments may include a plurality of steps or a plurality of stages, which are not necessarily performed at the same time, but may be performed at different times, and the order of the steps or stages is not necessarily performed sequentially, but may be performed alternately or alternately with at least some of the other steps or stages.
Based on the same inventive concept, the embodiment of the application also provides a vehicle nitrogen-oxygen sensor fault diagnosis device for realizing the vehicle nitrogen-oxygen sensor fault diagnosis method. The implementation of the solution provided by the device is similar to the implementation described in the above method, so the specific limitation in the embodiments of the device for diagnosing a vehicle nitrogen-oxygen sensor fault provided below may be referred to the limitation of the method for diagnosing a vehicle nitrogen-oxygen sensor fault hereinabove, and will not be repeated herein.
In one embodiment, as shown in fig. 5, there is provided a vehicle nitrogen-oxygen sensor malfunction diagnosis apparatus including: an average conversion efficiency determination module 510, an measured average acquisition module 520, a theoretical average determination module 530, and a fault determination module 540, wherein:
the average conversion efficiency determining module 510 is configured to determine an average conversion efficiency of the SCR system in a preset enabling period, where the preset enabling period is located in a period where a working condition of the SCR system is in a stable state;
the measured average value obtaining module 520 is configured to obtain a measured average value of a first nox concentration of the first nox sensor in a preset enabling period, and obtain a measured average value of a second nox concentration of the second nox sensor in the preset enabling period;
a theoretical average value determining module 530, configured to determine a theoretical average value of the nox concentration of the first nox sensor according to the average conversion efficiency and the actually measured average value of the second nox concentration;
the fault determining module 540 is configured to determine that the first nox sensor is faulty when a deviation between the measured average value of the first nox concentration and the theoretical average value of the nox concentration exceeds a preset deviation threshold.
In one embodiment, the theoretical average value determining module is further configured to determine a theoretical average value of the nox concentration according to a ratio of the second measured nox concentration average value to the nox residual rate; wherein the sum of the nitrogen oxide residual rate and the average conversion efficiency is 1.
In one embodiment, the average conversion efficiency determining module is further configured to determine the average conversion efficiency according to a ratio of a cumulative value of conversion efficiency of the SCR system over a preset enabling period to a cumulative number of times.
In one embodiment, the measured average value obtaining module is further configured to determine the measured average value of the first nox concentration according to a ratio of an accumulated value of the measured nox concentration values of the first nox sensor in the preset enabling period to the accumulated number of times.
In one embodiment, the vehicle nitrogen-oxygen sensor fault diagnosis further includes a deviation threshold correction module, configured to obtain an average carrier temperature of the SCR system during a preset enabling period, and compensate for a preset deviation threshold according to the average conversion efficiency and the average carrier temperature.
In one embodiment, the fault diagnosis of the vehicle nitrogen-oxygen sensor further comprises a working condition state judging module, which is used for acquiring working condition information of the SCR system; wherein, the operating mode information includes: environmental information, engine status information, actuator status information, and SCR system information;
Judging whether the working condition of the SCR system is in a stable state according to the working condition information, and determining the average conversion efficiency of the SCR system in a preset enabling period under the condition that the working condition of the SCR system is in the stable state.
The respective modules in the above-described vehicle nitrogen-oxygen sensor malfunction diagnosis apparatus may be implemented in whole or in part by software, hardware, and combinations thereof. The above modules may be embedded in hardware or may be independent of a processor in the computer device, or may be stored in software in a memory in the computer device, so that the processor may call and execute operations corresponding to the above modules.
In one embodiment, a computer device is provided comprising a memory and a processor, the memory having stored therein a computer program, the processor when executing the computer program performing the steps of:
determining the average conversion efficiency of the SCR system in a preset enabling period, wherein the preset enabling period is positioned in a period when the working condition of the SCR system is in a stable state;
acquiring a first nitrogen oxide concentration actual measurement average value of a first nitrogen oxide sensor in a preset enabling period, and acquiring a second nitrogen oxide concentration actual measurement average value of a second nitrogen oxide sensor in the preset enabling period;
Determining a theoretical average value of the nitrogen oxide concentration of the first nitrogen oxide sensor according to the average conversion efficiency and the actually measured average value of the second nitrogen oxide concentration;
and under the condition that the deviation between the measured average value of the first nitrogen oxide concentration and the theoretical average value of the nitrogen oxide concentration exceeds a preset deviation threshold value, determining that the first nitrogen oxide sensor fails.
In one embodiment, a computer readable storage medium is provided having a computer program stored thereon, which when executed by a processor, performs the steps of:
determining the average conversion efficiency of the SCR system in a preset enabling period, wherein the preset enabling period is positioned in a period when the working condition of the SCR system is in a stable state;
acquiring a first nitrogen oxide concentration actual measurement average value of a first nitrogen oxide sensor in a preset enabling period, and acquiring a second nitrogen oxide concentration actual measurement average value of a second nitrogen oxide sensor in the preset enabling period;
determining a theoretical average value of the nitrogen oxide concentration of the first nitrogen oxide sensor according to the average conversion efficiency and the actually measured average value of the second nitrogen oxide concentration;
and under the condition that the deviation between the measured average value of the first nitrogen oxide concentration and the theoretical average value of the nitrogen oxide concentration exceeds a preset deviation threshold value, determining that the first nitrogen oxide sensor fails.
In one embodiment, a computer program product is provided comprising a computer program which, when executed by a processor, performs the steps of:
determining the average conversion efficiency of the SCR system in a preset enabling period, wherein the preset enabling period is positioned in a period when the working condition of the SCR system is in a stable state;
acquiring a first nitrogen oxide concentration actual measurement average value of a first nitrogen oxide sensor in a preset enabling period, and acquiring a second nitrogen oxide concentration actual measurement average value of a second nitrogen oxide sensor in the preset enabling period;
determining a theoretical average value of the nitrogen oxide concentration of the first nitrogen oxide sensor according to the average conversion efficiency and the actually measured average value of the second nitrogen oxide concentration;
and under the condition that the deviation between the measured average value of the first nitrogen oxide concentration and the theoretical average value of the nitrogen oxide concentration exceeds a preset deviation threshold value, determining that the first nitrogen oxide sensor fails.
It should be noted that, the user information (including but not limited to user equipment information, user personal information, etc.) and the data (including but not limited to data for analysis, stored data, presented data, etc.) related to the present application are information and data authorized by the user or sufficiently authorized by each party, and the collection, use and processing of the related data need to comply with the related laws and regulations and standards of the related country and region.
Those skilled in the art will appreciate that implementing all or part of the above described methods may be accomplished by way of a computer program stored on a non-transitory computer readable storage medium, which when executed, may comprise the steps of the embodiments of the methods described above. Any reference to memory, database, or other medium used in embodiments provided herein may include at least one of non-volatile and volatile memory. The nonvolatile Memory may include Read-Only Memory (ROM), magnetic tape, floppy disk, flash Memory, optical Memory, high density embedded nonvolatile Memory, resistive random access Memory (ReRAM), magnetic random access Memory (Magnetoresistive Random Access Memory, MRAM), ferroelectric Memory (Ferroelectric Random Access Memory, FRAM), phase change Memory (Phase Change Memory, PCM), graphene Memory, and the like. Volatile memory can include random access memory (Random Access Memory, RAM) or external cache memory, and the like. By way of illustration, and not limitation, RAM can be in the form of a variety of forms, such as static random access memory (Static Random Access Memory, SRAM) or dynamic random access memory (Dynamic Random Access Memory, DRAM), and the like. The databases referred to in the embodiments provided herein may include at least one of a relational database and a non-relational database. The non-relational database may include, but is not limited to, a blockchain-based distributed database, and the like. The processor referred to in the embodiments provided in the present application may be a general-purpose processor, a central processing unit, a graphics processor, a digital signal processor, a programmable logic unit, a data processing logic unit based on quantum computing, or the like, but is not limited thereto.
The technical features of the above embodiments may be arbitrarily combined, and all possible combinations of the technical features in the above embodiments are not described for brevity of description, however, as long as there is no contradiction between the combinations of the technical features, they should be considered as the scope of the description.
The foregoing examples illustrate only a few embodiments of the application and are described in detail herein without thereby limiting the scope of the application. It should be noted that it will be apparent to those skilled in the art that several variations and modifications can be made without departing from the spirit of the application, which are all within the scope of the application. Accordingly, the scope of the application should be assessed as that of the appended claims.
Claims (10)
1. A vehicle nitrogen-oxygen sensor fault diagnosis method, the vehicle including an SCR system, and a first nitrogen-oxygen sensor located at an inlet end of the SCR system and a second nitrogen-oxygen sensor located at an outlet end of the SCR system, the method comprising:
determining average conversion efficiency of the SCR system in a preset enabling period, wherein the preset enabling period is positioned in a period when working conditions of the SCR system are in a stable state;
Acquiring a first nitrogen oxide concentration actual measurement average value of the first nitrogen oxide sensor in the preset enabling period, and acquiring a second nitrogen oxide concentration actual measurement average value of the second nitrogen oxide sensor in the preset enabling period;
determining a theoretical average value of the nitrogen oxide concentration of the first nitrogen oxide sensor according to the average conversion efficiency and the actually measured average value of the second nitrogen oxide concentration;
and under the condition that the deviation between the measured average value of the first nitrogen oxide concentration and the theoretical average value of the nitrogen oxide concentration exceeds a preset deviation threshold value, judging that the first nitrogen oxide sensor fails.
2. The vehicle nitrogen-oxygen sensor malfunction diagnosis method according to claim 1, wherein said determining a theoretical average value of the nitrogen oxide concentration of the first nitrogen-oxygen sensor based on the average conversion efficiency and the second actual average value of the nitrogen oxide concentration includes:
determining the theoretical average value of the nitrogen oxide concentration according to the ratio of the measured average value of the second nitrogen oxide concentration to the residual rate of nitrogen oxide; wherein the sum of the nitrogen oxide residual rate and the average conversion efficiency is 1.
3. The vehicle nitrogen-oxygen sensor malfunction diagnosis method according to any one of claims 1 to 2, wherein the determining of the average conversion efficiency of the SCR system in a preset enable period includes:
and determining the average conversion efficiency according to the ratio of the accumulated value of the conversion efficiency of the SCR system in the preset enabling period to the accumulated times.
4. The vehicle nitrogen-oxygen sensor malfunction diagnosis method according to claim 3, wherein the obtaining a first measured average value of the concentration of nitrogen oxides of the first nitrogen-oxygen sensor in the preset enabling period includes:
and determining the first nitrogen oxide concentration actual measurement average value according to the ratio of the accumulation value of the nitrogen oxide concentration actual measurement value of the first nitrogen oxide sensor in the preset enabling period to the accumulation times.
5. The vehicle nitrogen-oxygen sensor malfunction diagnosis method according to claim 1, wherein the determining before the first nitrogen-oxygen sensor malfunction in the case where the deviation of the first measured nox concentration average value from the theoretical nox concentration average value exceeds a preset deviation threshold value further includes:
and acquiring the average carrier temperature of the SCR system in the preset enabling period, and compensating the preset deviation threshold according to the average conversion efficiency and the average carrier temperature.
6. The vehicle nitrogen-oxygen sensor malfunction diagnosis method according to claim 1 or 5, characterized by further comprising:
acquiring working condition information of the SCR system; wherein, the operating mode information includes: environmental information, engine status information, actuator status information, and SCR system information;
judging whether the working condition of the SCR system is in a stable state according to the working condition information, and determining the average conversion efficiency of the SCR system in the preset enabling period under the condition that the working condition of the SCR system is in the stable state.
7. A vehicle nitrogen-oxygen sensor fault diagnosis apparatus, the vehicle including an SCR system, and a first nitrogen-oxygen sensor located at an inlet end of the SCR system and a second nitrogen-oxygen sensor located at an outlet end of the SCR system, the apparatus comprising:
the average conversion efficiency determining module is used for determining the average conversion efficiency of the SCR system in a preset enabling period, wherein the preset enabling period is positioned in a period in which the working condition of the SCR system is in a stable state;
the measured average value acquisition module is used for acquiring a first measured average value of the concentration of the nitrogen oxides of the first nitrogen oxide sensor in the preset enabling period and acquiring a second measured average value of the concentration of the nitrogen oxides of the second nitrogen oxide sensor in the preset enabling period;
The theoretical average value determining module is used for determining the theoretical average value of the nitrogen oxide concentration of the first nitrogen oxide sensor according to the average conversion efficiency and the actually measured average value of the second nitrogen oxide concentration;
the fault judging module is used for judging the first nitrogen-oxygen sensor to be faulty under the condition that the deviation between the measured average value of the first nitrogen oxide concentration and the theoretical average value of the nitrogen oxide concentration exceeds a preset deviation threshold value.
8. A computer device comprising a memory and a processor, the memory storing a computer program, characterized in that the processor, when executing the computer program, implements the steps of the vehicle nitrogen-oxygen sensor fault diagnosis method of any one of claims 1 to 6.
9. A computer-readable storage medium, on which a computer program is stored, characterized in that the computer program, when executed by a processor, implements the steps of the vehicle nitrogen-oxygen sensor malfunction diagnosis method according to any one of claims 1 to 6.
10. A computer program product comprising a computer program, characterized in that the computer program, when executed by a processor, implements the steps of the vehicle nitrogen-oxygen sensor fault diagnosis method of any one of claims 1 to 6.
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