CN115142995B - Method, device, system and storage medium for monitoring exhaust gas recirculation system - Google Patents
Method, device, system and storage medium for monitoring exhaust gas recirculation system Download PDFInfo
- Publication number
- CN115142995B CN115142995B CN202210824285.5A CN202210824285A CN115142995B CN 115142995 B CN115142995 B CN 115142995B CN 202210824285 A CN202210824285 A CN 202210824285A CN 115142995 B CN115142995 B CN 115142995B
- Authority
- CN
- China
- Prior art keywords
- exhaust gas
- gas recirculation
- value
- recirculation system
- differential pressure
- Prior art date
- Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
- Active
Links
- 238000000034 method Methods 0.000 title claims abstract description 38
- 238000012544 monitoring process Methods 0.000 title claims abstract description 38
- 230000008439 repair process Effects 0.000 claims description 24
- 239000007789 gas Substances 0.000 description 135
- 238000003745 diagnosis Methods 0.000 description 8
- 238000010586 diagram Methods 0.000 description 7
- 239000003054 catalyst Substances 0.000 description 6
- 230000007257 malfunction Effects 0.000 description 5
- 230000010354 integration Effects 0.000 description 4
- 239000000498 cooling water Substances 0.000 description 3
- 230000001360 synchronised effect Effects 0.000 description 3
- 238000012986 modification Methods 0.000 description 2
- 230000004048 modification Effects 0.000 description 2
- 238000012806 monitoring device Methods 0.000 description 2
- 230000000630 rising effect Effects 0.000 description 2
- 230000003068 static effect Effects 0.000 description 2
- 230000001174 ascending effect Effects 0.000 description 1
- 230000008859 change Effects 0.000 description 1
- 238000002485 combustion reaction Methods 0.000 description 1
- 238000004590 computer program Methods 0.000 description 1
- 238000002405 diagnostic procedure Methods 0.000 description 1
- 230000004069 differentiation Effects 0.000 description 1
- 239000003344 environmental pollutant Substances 0.000 description 1
- 239000000446 fuel Substances 0.000 description 1
- DOTMOQHOJINYBL-UHFFFAOYSA-N molecular nitrogen;molecular oxygen Chemical compound N#N.O=O DOTMOQHOJINYBL-UHFFFAOYSA-N 0.000 description 1
- 230000003287 optical effect Effects 0.000 description 1
- 239000013618 particulate matter Substances 0.000 description 1
- 231100000719 pollutant Toxicity 0.000 description 1
- 230000008569 process Effects 0.000 description 1
- 230000009467 reduction Effects 0.000 description 1
- 238000005070 sampling Methods 0.000 description 1
Classifications
-
- F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
- F02—COMBUSTION ENGINES; HOT-GAS OR COMBUSTION-PRODUCT ENGINE PLANTS
- F02M—SUPPLYING COMBUSTION ENGINES IN GENERAL WITH COMBUSTIBLE MIXTURES OR CONSTITUENTS THEREOF
- F02M26/00—Engine-pertinent apparatus for adding exhaust gases to combustion-air, main fuel or fuel-air mixture, e.g. by exhaust gas recirculation [EGR] systems
- F02M26/49—Detecting, diagnosing or indicating an abnormal function of the EGR system
-
- F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
- F02—COMBUSTION ENGINES; HOT-GAS OR COMBUSTION-PRODUCT ENGINE PLANTS
- F02M—SUPPLYING COMBUSTION ENGINES IN GENERAL WITH COMBUSTIBLE MIXTURES OR CONSTITUENTS THEREOF
- F02M26/00—Engine-pertinent apparatus for adding exhaust gases to combustion-air, main fuel or fuel-air mixture, e.g. by exhaust gas recirculation [EGR] systems
- F02M26/45—Sensors specially adapted for EGR systems
- F02M26/46—Sensors specially adapted for EGR systems for determining the characteristics of gases, e.g. composition
- F02M26/47—Sensors specially adapted for EGR systems for determining the characteristics of gases, e.g. composition the characteristics being temperatures, pressures or flow rates
-
- 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
- Y02T—CLIMATE CHANGE MITIGATION TECHNOLOGIES RELATED TO TRANSPORTATION
- Y02T10/00—Road transport of goods or passengers
- Y02T10/10—Internal combustion engine [ICE] based vehicles
- Y02T10/40—Engine management systems
Abstract
The application discloses a monitoring method, a device, a system and a storage medium of an exhaust gas recirculation system, wherein the method comprises the following steps: when the absolute value of the opening gradient of the electronic throttle valve is larger than the opening threshold value, starting a timer; when the time of the timer is smaller than the delay time threshold value, acquiring a reference signal and a differential pressure signal, wherein the reference signal is a pressure signal acquired in an intake manifold of the exhaust gas recirculation system, and the differential pressure signal is a difference value of the pressure signals acquired at different positions in an exhaust gas recirculation pipeline of the exhaust gas recirculation system; closing the timer when the time of the timer is greater than the delay time threshold and the absolute value of the opening gradient of the electronic throttle valve is smaller than the second opening threshold; diagnosing the exhaust gas recirculation system based on the reference signal and the differential pressure signal. The application diagnoses the exhaust gas recirculation system through the reference signal and the differential pressure signal, and can more accurately diagnose.
Description
Technical Field
The application relates to the technical field of vehicle control, in particular to a monitoring method, a device, a system, a vehicle and a storage medium of an Exhaust Gas Recirculation (EGR) system.
Background
In order to reduce fuel consumption and exhaust gases (typically nitrogen-oxygen containing gases (NO x ) For example, an exhaust gas recirculation system is mounted on an atkinson cycle engine. An on-board automatic diagnostic (on board diagnostics, OBD) system should monitor EGR flow for a vehicle equipped with an exhaust gas recirculation system according to national sixth stage automotive pollutant emission standards.
In the related art, a method for monitoring an exhaust gas recirculation system includes: and acquiring temperature rise values before and after introducing the EGR gas by an EGR temperature sensor in the EGR system, and judging whether the EGR system has airflow faults according to the temperature rise values.
However, because there is the cooling water route in the exhaust gas recirculation system, the cooling water route can influence the temperature of EGR gas to influence temperature sensor gathers and obtain the temperature, and then make the degree of accuracy that carries out the air current trouble monitoring through introducing the temperature rise value around the EGR gas lower, especially for the exhaust gas recirculation system who is applied to the atkinson cycle engine, the flow of gas is less, and the cooling water route is greater to the influence of temperature.
Disclosure of Invention
The application provides a method, a device, a system and a storage medium for monitoring an exhaust gas recirculation system, which can solve the problem of lower accuracy of the method for monitoring the exhaust gas recirculation system provided in the related technology.
In one aspect, an embodiment of the present application provides a method for monitoring an exhaust gas recirculation system, including:
when the absolute value of the opening gradient of the electronic throttle valve is larger than the opening threshold value, starting a timer;
when the time of the timer is smaller than the delay time threshold value, acquiring a reference signal and a pressure difference signal, wherein the reference signal is a pressure signal acquired in an intake manifold of an exhaust gas recirculation system, and the pressure difference signal is a difference value of the pressure signals acquired at different positions in an exhaust gas recirculation pipeline of the exhaust gas recirculation system;
closing the timer when the time of the timer is greater than the delay time threshold and the absolute value of the opening gradient of the electronic throttle valve is less than the opening threshold;
diagnosing the exhaust gas recirculation system based on the reference signal and the differential pressure signal.
In some embodiments, the acquiring the reference signal and the differential pressure signal comprises:
acquiring a first reference signal and a second reference signal, wherein the first reference signal is the maximum value of signals acquired by the air inlet manifold in the delay time, and the second reference signal is the minimum value of signals acquired by the air inlet manifold in the delay time;
and acquiring a first differential pressure signal and a second differential pressure signal, wherein the first differential pressure signal is the maximum value of the difference acquired in the delay time, and the second differential pressure signal is the minimum value of the difference acquired in the delay time.
In some embodiments, the diagnosing the exhaust gas recirculation system based on the reference signal and the differential pressure signal includes:
calculating a first difference between the first reference signal and the second reference signal;
calculating a second difference between the first differential pressure signal and the second differential pressure signal;
diagnosing the exhaust gas recirculation system based on the first and second differences.
In some embodiments, the diagnosing the exhaust gas recirculation system based on the first and second differences comprises:
when the first difference value is greater than a first amplitude threshold value and the second difference value is less than a second amplitude threshold value, incrementing a fault counter value, the fault counter value being used to characterize the number of times the exhaust gas recirculation system has failed in monitoring;
when the first difference value is greater than the first amplitude threshold value and the second difference value is not less than the second amplitude threshold value, incrementing a value of a repair counter, the repair counter being used to characterize the number of times the exhaust gas recirculation system is not faulty in monitoring;
diagnosing the exhaust gas recirculation system based on the value of the fault counter and the value of the repair counter.
In some embodiments, the diagnosing the exhaust gas recirculation system based on the value of the fault counter and the value of the repair counter comprises:
determining whether the value of the fault counter is greater than the value of the repair counter when the sum of the values of the fault counter and the repair counter is equal to a value threshold;
and when the value of the fault counter is larger than that of the repair counter, determining that the exhaust gas recirculation system has a low flow fault.
In some embodiments, the method further comprises:
when the value of the fault counter is not greater than the value of the repair counter, it is determined that the exhaust gas recirculation system is not experiencing a low flow fault.
In some embodiments, the differential pressure signal is a difference in pressure signals acquired at a first location and a second location in the exhaust gas recirculation conduit;
the first position is located in a conduit on an intake side of an EGR valve in the exhaust gas recirculation conduit, and the second position is located in a conduit on an outlet side of the EGR valve.
In some embodiments, the first location is between the EGR valve and an EGR cooler in the exhaust gas recirculation conduit.
In one aspect, an embodiment of the present application provides a monitoring apparatus, including:
the judging module is used for starting the timer when the absolute value of the opening gradient of the electronic throttle valve is larger than the opening threshold value;
the acquisition module is used for acquiring a reference signal and a pressure difference signal when the time of the timer is smaller than a delay time threshold value, wherein the reference signal is a pressure signal acquired in an intake manifold of an exhaust gas recirculation system, and the pressure difference signal is a difference value of the pressure signals acquired at different positions in an exhaust gas recirculation pipeline of the exhaust gas recirculation system;
the judging module is further used for closing the timer when the time of the timer is larger than the delay time threshold and the absolute value of the opening gradient of the electronic throttle valve is smaller than a second opening threshold;
and the diagnosis module is used for diagnosing the exhaust gas recirculation system according to the reference signal and the differential pressure signal.
In one aspect, an embodiment of the present application provides a control system, where the control system includes a processor and a memory, where the memory stores at least one instruction or program, and the instruction or program is loaded and executed by the processor to implement a method for monitoring an exhaust gas recirculation system according to any one of the above.
In one aspect, embodiments of the present application provide a vehicle including an exhaust gas recirculation system and a control system as described above.
In one aspect, embodiments of the present application provide a computer readable storage medium having stored therein at least one instruction that is loaded and executed by a processor to implement a method of monitoring an exhaust gas recirculation system as described in any of the above.
The technical scheme of the application at least comprises the following advantages:
when the absolute value of the opening gradient of the electronic throttle valve is larger than the opening threshold value, a reference signal of the air inlet manifold and a differential pressure signal of the differential pressure sensor are obtained in the delay time, and when the delay time is over and the absolute value of the opening gradient of the electronic throttle valve is smaller than the second opening threshold value, the exhaust gas recirculation system is diagnosed according to the reference signal and the differential pressure signal, and as the signals of the air inlet manifold and the differential pressure sensor can reflect the flow condition of EGR gas, the flow fault of the exhaust gas recirculation system can be accurately diagnosed; meanwhile, the signal required for diagnosis is acquired under the condition that the absolute value of the opening gradient of the electronic throttle valve is larger than the opening threshold value, so that the fault can be diagnosed more accurately.
Drawings
In order to more clearly illustrate the embodiments of the present application or the technical solutions in the prior art, the drawings that are needed in the description of the embodiments or the prior art will be briefly described, and it is obvious that the drawings in the description below are some embodiments of the present application, and other drawings can be obtained according to the drawings without inventive effort for a person skilled in the art.
FIG. 1 is a schematic illustration of an exhaust gas recirculation system provided in accordance with an exemplary embodiment of the present application;
FIG. 2 is a schematic illustration of signals acquired during normal conditions of an EGR circuit;
FIG. 3 is a schematic illustration of signals acquired during a condition of an EGR circuit in the presence of a flow failure;
FIG. 4 is a flow chart of a method of monitoring an exhaust gas recirculation system according to an exemplary embodiment of the present application;
FIG. 5 is a flow chart of a method of monitoring an exhaust gas recirculation system according to an exemplary embodiment of the present application;
FIG. 6 is a flow chart of a method of monitoring an exhaust gas recirculation system according to an exemplary embodiment of the present application;
FIG. 7 is a block diagram of a monitoring device provided in an exemplary embodiment of the present application;
fig. 8 is a block diagram of a control system provided by an exemplary embodiment of the present application.
Detailed Description
The following description of the embodiments of the present application will be made more apparent and fully hereinafter with reference to the accompanying drawings, in which some, but not all embodiments of the application are shown. All other embodiments, which can be made by those skilled in the art based on the embodiments of the application without making any inventive effort, are intended to be within the scope of the application.
In the description of the present application, it should be noted that the directions or positional relationships indicated by the terms "center", "upper", "lower", "left", "right", "vertical", "horizontal", "inner", "outer", etc. are based on the directions or positional relationships shown in the drawings, are merely for convenience of describing the present application and simplifying the description, and do not indicate or imply that the devices or elements referred to must have a specific orientation, be configured and operated in a specific orientation, and thus should not be construed as limiting the present application. Furthermore, the terms "first," "second," and "third" are used for descriptive purposes only and are not to be construed as indicating or implying relative importance.
In the description of the present application, it should be noted that, unless explicitly specified and limited otherwise, the terms "mounted," "connected," and "connected" are to be construed broadly, and may be either fixedly connected, detachably connected, or integrally connected, for example; can be mechanically or electrically connected; the two components can be directly connected or indirectly connected through an intermediate medium, or can be communicated inside the two components, or can be connected wirelessly or in a wired way. The specific meaning of the above terms in the present application will be understood in specific cases by those of ordinary skill in the art.
In addition, the technical features of the different embodiments of the present application described below may be combined with each other as long as they do not collide with each other.
Referring to FIG. 1, a schematic diagram of an exhaust gas recirculation system provided by an exemplary embodiment of the present application is shown. Illustratively, as shown in FIG. 1, the exhaust gas recirculation system includes an intake conduit 101, an intake manifold 1021, an outlet manifold 1022, an exhaust conduit 103, and an exhaust gas recirculation conduit 104.
A throttle valve 111 is provided in the intake pipe 101, an EGR valve 112 and an EGR cooler 113 are provided in the exhaust gas recirculation pipe 104, a catalyst 114 and a particulate trap (gasoline particulate filter, GPF) 115 are provided in the exhaust pipe 103, and the exhaust gas recirculation system is connected to the engine 120 through an intake manifold 1021 and an exhaust manifold 1022. Wherein a throttle 111 is used to condition fresh air entering the intake conduit 101, an EGR cooler 113 (which is an optional device) is used to cool high temperature exhaust gases, an EGR valve 112 is used to condition gases in the exhaust gas recirculation conduit 104, a catalyst 114 is used to treat exhaust gases exiting the engine 120, and a GPF115 is used to trap particulate matter in the gases in the exhaust conduit 103. Optionally, an EGR temperature sensor is also provided in the exhaust gas recirculation conduit 104 for the temperature of the gas in the exhaust gas recirculation conduit 104.
The direction of flow of the gas through the exhaust gas recirculation system and the engine 120 is shown by the thick arrows in fig. 1: fresh air enters from an air inlet, passes through a throttle valve 111 and then enters an engine 120 through an air inlet manifold 1021 for combustion, and exhaust gas discharged from the engine 120 sequentially passes through an air outlet manifold 1022 and a catalyst 114 and then is discharged to the outside after passing through a GPF115, and part of the exhaust gas enters an exhaust gas recirculation pipeline (the gas entering the exhaust gas recirculation pipeline through the catalyst 114 is called EGR gas in the application), and the EGR gas sequentially passes through an EGR cooler 113 and an EGR valve 112 and then is combined with the fresh air in the air inlet manifold 1021 and enters the engine 120, so that the exhaust gas recirculation is realized.
A pressure sensor 1161 is disposed in the intake manifold 1021, and the pressure sensor 1161 is configured to collect a pressure signal in the intake manifold 1021, where the pressure signal may be used as a reference signal for characterizing the gas pressure in the intake manifold 1021 according to an embodiment of the present application; there are collection points of differential pressure sensor 1162 at different locations in exhaust gas recirculation conduit 104, and differential pressure sensor 1162 is configured to calculate differences in pressure signals collected at the collection points at the different locations to obtain differential pressure signals, which are used to characterize differential pressures of gases at the different locations in exhaust gas recirculation conduit 104.
Optionally, the collection point of the differential pressure sensor 1162 is located at a first location in the conduit on the intake side of the EGR valve 112 (e.g., between the EGR valve 112 and the EGR cooler 113 as shown in fig. 1) and a second location in the conduit on the exhaust side of the EGR valve 112.
The signals obtained by the pressure sensor 1161 and the differential pressure sensor 1162 may be fed back to a control system (for example, the control system may be an electronic controller (electronic control unit, ECU, not shown in fig. 1)) provided in the vehicle, while the control system may obtain the opening gradient of the throttle valve 111, and the exhaust gas recirculation system may be diagnosed by any one of the following method embodiments based on the signals obtained by the pressure sensor 1161 and the differential pressure sensor 1162 and the opening gradient of the throttle valve 111.
In the embodiment of the present application, the positions of the throttle valve 111, the EGR valve 112, the EGR cooler 113, the catalyst 114, and the GPF115, and the connection manner of the respective air pipes and the engine 120 are merely exemplary embodiments, and the embodiment of the present application is not limited thereto, and does not affect the diagnosis of the exhaust gas recirculation system by any of the following method embodiments.
In some embodiments, the EGR gas flow rate may be calculated from the signal obtained by the differential pressure sensor 1162 and the opening of the EGR valve 112, and the EGR gas flow rate may be used to diagnose the EGR system.
For example, based on the EGR rate demand of the engine 120 under each condition, a demanded EGR target flow may be calculated, the EGR target flow being relatively stable when the engine 120 is operating in a preset speed interval and torque interval, the EGR flow being integrated after a preset period of time when the diagnostic condition is met and the EGR flow is greater than a threshold, a deviation between the integration of the EGR flow and the integration of the target flow being calculated when the integration time meets the threshold, the deviation being divided by the integration of the target flow to obtain a deviation percentage, the EGR flow being represented as normal when the average of the deviation percentages is greater than the threshold; in contrast, when the engine operates in a preset rotating speed interval and torque interval, the EGR target flow is relatively stable, when the diagnosis condition is met and the EGR flow is larger than the threshold value, the deviation between the integral of the EGR flow and the integral of the target flow is calculated when the opening of the EGR valve 112 is larger than the limit opening threshold value, the deviation percentage is obtained by dividing the integral of the target flow, and when the average value of the deviation percentages is smaller than the threshold value, the low flow fault of the exhaust gas recirculation system is confirmed.
However, the above diagnostic methods have drawbacks in that: it requires a large flow rate of EGR gas in a continuous period of time to obtain the integral of the EGR flow rate and the integral of the target flow rate with a sufficient degree of differentiation in a short period of time, and the engine 120 in the exhaust gas recirculation system has a small vacuum degree of the medium-small load manifold, and is configured with a high-pressure exhaust gas recirculation technology, so that it is difficult to satisfy the large flow rate passing in a continuous period of time, and it is difficult to make diagnosis.
Based on the above reasons, the application provides a method for monitoring an exhaust gas recirculation system under a dynamic working condition, which is characterized in that a diagnosis mode is started under a specific working condition (the absolute value of the opening gradient of an electronic throttle valve is larger than an opening threshold value), a reference signal of an intake manifold and a differential pressure signal of a differential pressure sensor are obtained within a preset delay time, and the flow fault of EGR gas in the exhaust gas recirculation system is diagnosed according to the reference signal and the differential pressure signal, so that the fault can be diagnosed more accurately and precisely.
As shown in fig. 1, in the exhaust gas recirculation system, after the exhaust gas passes through the catalyst, it sequentially passes through the EGR cooler 113 and the EGR valve 112 and then enters the intake manifold 1021, one collection point of the differential pressure sensor 1162 is on the intake side and is located between the EGR valve 112 and the cooler 113, another collection point of the differential pressure sensor 1162 is on the outlet side and is located in a pipe behind the EGR valve 112 and is located on the side close to the intake manifold 1021, a differential pressure signal between the two collection points can be obtained by using the differential pressure sensor 1162, and a pressure signal of the gas in the intake manifold 1021 can be obtained by using the pressure sensor 1161.
Referring to fig. 2, a schematic diagram of the signals acquired during normal conditions of the exhaust gas recirculation circuit is shown. As shown in fig. 2, it shows a first pressure signal acquired by a differential pressure sensor at an acquisition point on an intake side, a second pressure signal acquired by a differential pressure sensor at an acquisition point on an exhaust side, a reference signal acquired by a pressure sensor provided in an intake manifold, and a differential pressure signal between the first pressure signal and the second pressure signal, and the abscissa is time.
When the exhaust gas recirculation pipeline has no fault, the differential pressure sensor is communicated with the air inlet manifold at the collecting point of the air outlet side, and the pressure of the air in the air outlet side pipeline is close to the pressure of the air in the air inlet manifold; the pressure difference sensor is communicated with the EGR cooler and the exhaust pipeline at the collecting point of the air inlet side, and the pressure of the gas is close to the back pressure of the catalyzed gas. The pressure difference signal obtained by the pressure difference sensor is the difference value of the pressure signal obtained by the collection point at the air outlet side and the collection point at the air inlet side, and in general, in the stage of rapid opening of a throttle valve (the absolute value of the opening gradient of the throttle valve is larger), if the pressure of the gas in the pipeline at the air inlet side is stable, the rising of the gas pressure in the air inlet manifold can cause the rising of the pressure signal obtained by the collection point at the air outlet side, so that the pressure difference signal is reduced; in the rapid closing stage of the throttle valve, if the pressure of the gas in the pipeline at the air inlet side is stable, the pressure signal acquired by the acquisition point at the air outlet side is reduced due to the reduction of the gas pressure in the air inlet manifold, and then the pressure difference signal is increased.
Therefore, when there is no fault in the EGR line, the EGR valve is opened, the amplitude of the reference signal acquired by the pressure sensor in the intake manifold and the amplitude of the differential pressure signal are synchronous and opposite in direction, as shown in fig. 2, A1 is the amplitude of the reference signal acquired by the pressure sensor in the intake manifold when the reference signal falls, A2 is the amplitude of the reference signal when the reference signal rises, A3 is the amplitude of the differential pressure signal when the differential pressure signal rises, A4 is the amplitude of the differential pressure signal when the differential pressure signal falls, A1 and A3 are synchronous and opposite, A2 and A4 are synchronous and opposite, A1 and A3 correspond to the fast throttle closing stage (the stage corresponding to the left broken line ellipse) and A2 and A4 correspond to the fast throttle opening stage (the stage corresponding to the right broken line ellipse).
Referring to fig. 3, a schematic diagram of the signals acquired in the case of a flow failure in the exhaust gas recirculation circuit is shown. As shown in fig. 3, it shows a first pressure signal acquired by a differential pressure sensor at an acquisition point on an intake side, a second pressure signal acquired by a differential pressure sensor at an acquisition point on an exhaust side, a reference signal acquired by a pressure sensor provided in an intake manifold, and a differential pressure signal between the first pressure signal and the second pressure signal, and the abscissa is time.
In the case where there is a failure in the exhaust gas recirculation line (for example, the exhaust gas recirculation line is clogged), when the EGR valve is opened, the differential pressure sensor communicates between the collection point on the intake side and the collection point on the outlet side, and the differential pressure generated across the EGR valve is small because the flow rate of the exhaust gas is small when the line is clogged. During the rapid change phase of the electronic throttle valve, the pressure difference across the EGR valve remains small, regardless of whether the pressure of the gas in the intake manifold rises or falls. Therefore, when the EGR valve is opened and the pressure signal at the intake manifold has an amplitude, the differential pressure signal does not have an obvious amplitude, as shown in fig. 3, A1 is the amplitude of the reference signal acquired by the pressure sensor in the intake manifold when the reference signal is descending, A2 is the amplitude of the reference signal when the reference signal is ascending, A1 corresponds to the rapid open-up stage (stage corresponding to the left-hand broken-line ellipse), A2 corresponds to the rapid close-down stage (stage corresponding to the right-hand broken-line ellipse) of the throttle, and the differential pressure signal does not have an obvious amplitude in the whole process.
As described above, in the exhaust gas recirculation line, in the case where there is no fault and in the case where there is a flow fault, the following performance of the differential pressure signal and the reference signal is different after the EGR valve is opened.
Referring to fig. 4, a flowchart of a method for monitoring an exhaust gas recirculation system according to an exemplary embodiment of the present application is shown, which may be performed by the control system according to the above embodiment, as shown in fig. 4, and includes:
in step 401, a timer is started when an absolute value of an opening gradient of the electronic throttle valve is greater than an opening threshold.
The opening threshold value can be set according to actual sampling data of the exhaust gas recirculation system, and the state of the electronic throttle valve when the opening gradient is larger than the opening threshold value is correspondingly a stage of quick opening or quick opening of the electronic throttle valve. While the timer is started, step 402 is entered to obtain a reference signal and a differential pressure signal.
In step 402, a reference signal and a differential pressure signal are acquired when the time of the timer is less than a delay time threshold.
Wherein, as mentioned above, the reference signal is a pressure signal acquired in an intake manifold of the exhaust gas recirculation system, and the differential pressure signal is a difference value of the pressure signals acquired at different positions in an exhaust gas recirculation pipe of the exhaust gas recirculation system. The reference signal and the differential pressure signal may be obtained by referring to the above, and will not be described herein.
As described above, in the stage where the electronic throttle valve is rapidly opened or rapidly opened, the reference signal and the differential pressure signal both have significant amplitudes in the case where there is no malfunction of the exhaust gas recirculation line, and the reference signal has significant amplitudes and the differential pressure signal does not have significant amplitudes in the case where there is a malfunction of the exhaust gas recirculation line, so that the malfunction problem of the exhaust gas recirculation system can be accurately and precisely diagnosed by acquiring the required data when the absolute value of the opening gradient of the electronic throttle valve is greater than the opening threshold value.
In step 403, when the time of the timer is greater than the delay time threshold and the absolute value of the opening gradient of the electronic throttle valve is less than the opening threshold, the timer is turned off.
The delay time threshold is a preset signal acquisition time, and the signal acquisition step may be stopped according to an actual setting of the delay time threshold (for example, it is usually a time for which the electronic throttle valve is rapidly opened or closed), when the time of the timer is within the delay time threshold and the absolute value of the opening gradient of the electronic throttle valve is smaller than the opening threshold, data acquisition may be performed, and when the time of the timer is greater than the delay time threshold and the absolute value of the opening gradient of the electronic throttle valve is monitored to be smaller than the opening threshold (which indicates that the electronic throttle valve is not in a stage of rapid opening or rapid opening).
Step 404, diagnosing the exhaust gas recirculation system based on the reference signal and the differential pressure signal.
As described above, the EGR valve is opened with the differential pressure signal and the reference signal having different followability in both cases of no malfunction and flow malfunction, so that the EGR system can be diagnosed based on the differential pressure signal and the reference signal.
In summary, in the embodiment of the present application, when the absolute value of the opening gradient of the electronic throttle valve is greater than the opening threshold, the reference signal of the intake manifold and the differential pressure signal of the differential pressure sensor are obtained in the delay time, and when the delay time is over and the absolute value of the opening gradient of the electronic throttle valve is less than the second opening threshold, the exhaust gas recirculation system is diagnosed according to the reference signal and the differential pressure signal, and since the signals of the intake manifold and the differential pressure sensor can reflect the flow condition of the EGR gas, the flow fault of the exhaust gas recirculation system can be accurately diagnosed; meanwhile, the signal required for diagnosis is acquired under the condition that the absolute value of the opening gradient of the electronic throttle valve is larger than the opening threshold value, so that the fault can be diagnosed more accurately.
Referring to fig. 5, which is a flowchart illustrating a method for monitoring an exhaust gas recirculation system according to an exemplary embodiment of the present application, which may be performed by the control system of the above-described embodiment, the method may be an alternative implementation of the embodiment of fig. 4, as shown in fig. 5, and the method includes:
step 501, it is determined whether the absolute value of the opening gradient of the electronic throttle valve is greater than an opening threshold.
When the absolute value of the opening gradient of the electronic throttle valve is not greater than the opening threshold value, the electronic throttle valve is not in a stage of rapid opening or rapid opening, and the signals acquired in the stage lack obvious characteristics, so that the signals are not suitable for signal acquisition, and the step 501 is continuously executed; when the absolute value of the opening gradient of the electronic throttle valve is greater than the opening threshold, it indicates that the electronic throttle valve is in a stage of rapid opening or rapid opening, and signal acquisition can be performed, and step 502 is entered.
Step 502, a timer is started.
When the timer is started, signal acquisition is performed.
In step 503, a first reference signal and a second reference signal are obtained, where the first reference signal is a maximum value of the pressure signal collected in the intake manifold, and the second reference signal is a minimum value of the pressure signal collected in the intake manifold.
Before the timer is closed, the pressure signal in the air inlet manifold is continuously collected, and is subjected to large-scale acquisition to obtain a first reference signal Psmax, and is subjected to small-scale acquisition to obtain a second reference signal Psmin.
Step 504, acquiring a first differential pressure signal and a second differential pressure signal, wherein the first differential pressure signal is the maximum value of the acquired differential pressure signal, and the second differential pressure signal is the minimum value of the acquired differential pressure signal.
Before the timer is closed, continuously collecting pressure signals of the first position and the second position, calculating a pressure signal difference value at the same moment to obtain a pressure difference signal, and obtaining a first pressure difference signal Pegrmax by taking the pressure difference signal big and a second pressure difference signal Pegrmin by taking the pressure difference signal small.
The execution order of steps 503 and 504 is not limited. An exemplary illustration of step 503 followed by step 504 is shown in fig. 5.
In step 505, it is determined whether the time of the timer is greater than a delay time threshold.
As described above, the delay time threshold is a preset signal acquisition time, and the delay time threshold may be set according to the actual situation, and when the time of the timer is not greater than the delay time threshold, step 503 and step 504 are continuously executed to perform signal acquisition; when the time of the timer is greater than the delay time threshold, step 506 is entered.
Step 506 determines whether the absolute value of the opening gradient of the electronic throttle valve is less than an opening threshold.
As described above, when the absolute value of the opening gradient of the electronic throttle valve is not less than the opening threshold, the electronic throttle valve can be considered to be still in the stage of rapid opening or rapid opening, and signal acquisition can be continued; when the time of the timer is greater than the delay time threshold and the absolute value of the opening gradient of the electronic throttle valve is less than the opening threshold, the electronic throttle valve is not in the stage of rapid opening or rapid opening and small, and the step 507 is entered.
The execution sequence of steps 505 and 506 is not limited. An exemplary illustration of step 505 followed by step 506 is shown in fig. 5.
Step 507, the timer is closed.
And when the timer is closed, stopping signal acquisition.
Step 508, a first difference between the first reference signal and the second reference signal is calculated.
As described above, the amplitude A1 or A2 of the reference signal at the stage where the electronic throttle valve is still in the rapid opening or the rapid opening is obtained by calculating the first difference Δps between the first reference signal and the second reference signal.
Step 509 calculates a second difference between the first differential pressure signal and the second differential pressure signal.
As described above, the amplitude A3 or A4 of the reference signal at the stage where the electronic throttle valve is still in the rapid opening or the rapid opening is obtained by calculating the second difference Δpegr between the first differential pressure signal and the second differential pressure signal.
The execution sequence of step 508 and step 509 is not limited. An exemplary illustration of step 508 followed by step 509 is shown in fig. 5.
At step 510, diagnosing the exhaust gas recirculation system based on the first and second differences.
As described above, the exhaust gas recirculation system may be diagnosed based on the first and second differences based on the difference in the following characteristics of the differential pressure signal and the reference signal after the EGR valve is opened in both cases where there is no fault and where there is a flow fault in the exhaust gas recirculation line. The diagnosis mode may be set according to the actual requirement, for example, a threshold value of a first difference Δps may be preset, defined as a first amplitude threshold value, a threshold value of a second difference Δpegr may be preset, defined as a second amplitude threshold value, and when Δps is greater than the first amplitude threshold value and Δpegr is greater than the second amplitude threshold value, it is indicated that there is no low flow fault in the exhaust gas recirculation system, and if it is not satisfied, it is indicated that there is a low flow fault in the exhaust gas recirculation system.
However, in practice, the exhaust gas recirculation line may occasionally fail or there may be some problem in signal acquisition, and in this regard, the embodiment of fig. 6 provides a more accurate monitoring.
Referring to FIG. 6, which illustrates a flow chart of a method of monitoring an exhaust gas recirculation system according to an exemplary embodiment of the present application, which may be performed by the control system of the above-described embodiment, the method may be an alternative implementation of step 510 of the embodiment of FIG. 5, as shown in FIG. 6, and which includes:
in step 5101, it is determined whether the first difference is greater than a first amplitude threshold.
As described above, regardless of whether the exhaust gas recirculation pipe is faulty, when the electronic throttle valve is still in the fast open or fast open stage, the first difference between the first reference signal and the second reference signal should be greater than the first amplitude threshold, so when the first difference is not greater than the first amplitude threshold, signal acquisition needs to be performed again, and step 501 is entered; when the first difference is greater than the first amplitude threshold, step 5102 is entered.
In step 5102, it is determined whether the second difference is less than a second amplitude threshold.
As described above, when the exhaust gas recirculation line fails, the differential pressure signal does not have a significant magnitude, which is indicative of the second difference being less than the second magnitude threshold, and proceeds to step 5103a; when there is no fault in the exhaust gas recirculation conduit, the differential pressure signal has a significant magnitude that is indicative of the second difference not being less than the second magnitude threshold, and proceeds to step 5103b.
In step 5103a, the value of the fault counter is incremented by one.
Wherein the fault counter is used to characterize the number of times the exhaust gas recirculation system has failed in the monitoring.
In step 5103b, the value of the repair counter is incremented by one.
Wherein the repair counter is used to characterize the number of times the exhaust gas recirculation system is not malfunctioning in the monitoring.
In step 5104, it is determined whether the sum of the values of the fault counter and the repair counter is equal to a value threshold.
The numerical threshold is a preset fault monitoring number, and the more the number is, the more accurate the monitoring result is, but the longer the time is, the numerical value can be set according to actual requirements. When the sum of the values of the fault counter and the repair counter is equal to the value threshold, the fault monitoring is finished, and step 5105 is performed; when the sum of the values of the fault counter and the repair counter is smaller than the value threshold, it is indicated that the fault monitoring is not completed, and the monitoring needs to be continued, and step 501 is entered.
In step 5105, it is determined whether the value of the failure counter is greater than the value of the repair counter.
When the value of the fault counter is greater than the value of the repair counter, it may be determined that the exhaust gas recirculation system has a low flow fault, and step 5106a is entered; when the value of the fault counter is not greater than the value of the repair counter, it may be determined that the exhaust gas recirculation system is not experiencing a low flow fault, and step 5106b is entered.
In step 5106a, it is determined that there is a low flow fault in the exhaust gas recirculation system.
In step 5106b, it is determined that there is no low flow fault in the exhaust gas recirculation system.
When the exhaust gas recirculation system is determined to have a low flow fault, the monitoring result can be reported through an OBD fault code or an OBD fault lamp.
Referring to fig. 7, a block diagram of a monitoring device according to an exemplary embodiment of the present application is shown, which may be implemented as a control system in the above-described embodiment by software, hardware, or a combination of both. The device comprises:
a decision module 710 for performing steps 401, 403, 501, 502, 505, 506, 507, and other decision steps performed by the control system.
The obtaining module 720 is configured to perform step 402, step 503, step 504, and other data obtaining steps performed by the control system.
Diagnostic module 730 for executing steps 508, 509, 510, 5101, 5102, 5103a, 5103b, 5104, 5105, 5106a, 5106b and other diagnostic steps performed by the control system.
Referring to fig. 8, a block diagram of a control system provided by an exemplary embodiment of the present application is shown. As shown in fig. 8, the control system includes: processor 810 and memory 820.
The processor 810 may be a central processing unit (central processing unit, CPU), a network processor (network processor, NP) or a combination of CPU and NP. The processor 810 may further include a hardware chip. The hardware chip may be an application-specific integrated circuit (ASIC), a programmable logic device (programmable logic device, PLD), or a combination thereof. The PLD may be a complex programmable logic device (complex programmable logic device, CPLD), a field-programmable gate array (field-programmable gate array, FPGA), general-purpose array logic (generic array logic, GAL), or any combination thereof.
The memory 820 is connected to the processor 810 by a bus or other means, and at least one instruction, at least one program, code set, or instruction set is stored in the memory 820, and the at least one instruction, at least one program, code set, or instruction set is loaded and executed by the processor 810 to implement the method for monitoring an exhaust gas recirculation system as provided in any of the embodiments above. The memory 820 may be volatile memory (volatile memory), non-volatile memory (non-volatile memory), or a combination thereof. The volatile memory may be a random-access memory (RAM), such as a static random-access memory (static random access memory, SRAM), a dynamic random-access memory (dynamic random access memory, DRAM). The non-volatile memory may be a read-only memory (read only memory image, ROM), such as a programmable read-only memory (programmable read only memory, PROM), an erasable programmable read-only memory (erasable programmable read only memory, EPROM), an electrically erasable programmable read-only memory (electrically erasable programmable read-only memory, EEPROM). The nonvolatile memory may also be a flash memory (flash memory), a magnetic memory such as a magnetic tape (magnetic tape), a floppy disk (floppy disk), and a hard disk. The non-volatile memory may also be an optical disc.
The application also provides a vehicle equipped with the exhaust gas recirculation system and the control system provided in any of the above embodiments.
The present application also provides a computer readable storage medium having stored therein at least one instruction, at least one program, a set of codes, or a set of instructions, the at least one instruction, the at least one program, the set of codes, or the set of instructions being loaded and executed by the processor to implement a method of monitoring an exhaust gas recirculation system according to any one of the embodiments described above.
The application also provides a computer program product which, when run on a computer, causes the computer to perform the method for monitoring an exhaust gas recirculation system provided by the above-mentioned respective method embodiments.
It is apparent that the above examples are given by way of illustration only and are not limiting of the embodiments. Other variations or modifications of the above teachings will be apparent to those of ordinary skill in the art. It is not necessary here nor is it exhaustive of all embodiments. While still being apparent from variations or modifications that may be made by those skilled in the art are within the scope of the application.
Claims (9)
1. A method of monitoring an exhaust gas recirculation system, comprising:
when the absolute value of the opening gradient of the electronic throttle valve is larger than the opening threshold value, starting a timer;
when the time of the timer is smaller than the delay time threshold value, acquiring a reference signal and a pressure difference signal, wherein the reference signal is a pressure signal acquired in an intake manifold of an exhaust gas recirculation system, and the pressure difference signal is a difference value of the pressure signals acquired at different positions in an exhaust gas recirculation pipeline of the exhaust gas recirculation system;
closing the timer when the time of the timer is greater than the delay time threshold and the absolute value of the opening gradient of the electronic throttle valve is less than a second opening threshold;
diagnosing the exhaust gas recirculation system based on the reference signal and the differential pressure signal;
the acquiring the reference signal and the differential pressure signal includes:
acquiring a first reference signal and a second reference signal, wherein the first reference signal is the maximum value of a pressure signal acquired in the air inlet manifold, and the second reference signal is the minimum value of the pressure signal acquired in the air inlet manifold;
acquiring a first differential pressure signal and a second differential pressure signal, wherein the first differential pressure signal is the maximum value of the acquired differential pressure signal, and the second differential pressure signal is the minimum value of the acquired differential pressure signal;
the diagnosing the exhaust gas recirculation system based on the reference signal and the differential pressure signal includes:
calculating a first difference between the first reference signal and the second reference signal;
calculating a second difference between the first differential pressure signal and the second differential pressure signal;
diagnosing the exhaust gas recirculation system based on the first and second differences.
2. The method of claim 1, wherein diagnosing the exhaust gas recirculation system based on the first difference and the second difference comprises:
when the first difference value is greater than a first amplitude threshold value and the second difference value is less than a second amplitude threshold value, incrementing a fault counter value, the fault counter value being used to characterize the number of times the exhaust gas recirculation system has failed in monitoring;
when the first difference value is greater than the first amplitude threshold value and the second difference value is not less than the second amplitude threshold value, incrementing a value of a repair counter, the repair counter being used to characterize the number of times the exhaust gas recirculation system is not faulty in monitoring;
diagnosing the exhaust gas recirculation system based on the value of the fault counter and the value of the repair counter.
3. The method of claim 2, wherein diagnosing the exhaust gas recirculation system based on the value of the fault counter and the value of the repair counter comprises:
determining whether the value of the fault counter is greater than the value of the repair counter when the sum of the values of the fault counter and the repair counter is equal to a value threshold;
and when the value of the fault counter is larger than that of the repair counter, determining that the exhaust gas recirculation system has a low flow fault.
4. A method according to claim 3, characterized in that the method further comprises:
when the value of the fault counter is not greater than the value of the repair counter, it is determined that the exhaust gas recirculation system is not experiencing a low flow fault.
5. The method of any one of claims 1 to 4, wherein the differential pressure signal is a difference in pressure signals acquired at a first location and a second location in the exhaust gas recirculation conduit;
the first position is located in a conduit on an intake side of an EGR valve in the exhaust gas recirculation conduit, and the second position is located in a conduit on an outlet side of the EGR valve.
6. The method of claim 5, wherein the first location is between the EGR valve and an EGR cooler in the exhaust gas recirculation conduit.
7. A control system, characterized in that it comprises a processor and a memory in which at least one instruction or program is stored, which is loaded and executed by the processor to implement the method of monitoring an exhaust gas recirculation system according to any one of claims 1 to 6.
8. A vehicle comprising an exhaust gas recirculation system and the control system of claim 7.
9. A computer readable storage medium having stored therein at least one instruction that is loaded and executed by a processor to implement the method of monitoring an exhaust gas recirculation system according to any one of claims 1 to 6.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN202210824285.5A CN115142995B (en) | 2022-07-13 | 2022-07-13 | Method, device, system and storage medium for monitoring exhaust gas recirculation system |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN202210824285.5A CN115142995B (en) | 2022-07-13 | 2022-07-13 | Method, device, system and storage medium for monitoring exhaust gas recirculation system |
Publications (2)
| Publication Number | Publication Date |
|---|---|
| CN115142995A CN115142995A (en) | 2022-10-04 |
| CN115142995B true CN115142995B (en) | 2023-11-10 |
Family
ID=83411292
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CN202210824285.5A Active CN115142995B (en) | 2022-07-13 | 2022-07-13 | Method, device, system and storage medium for monitoring exhaust gas recirculation system |
Country Status (1)
| Country | Link |
|---|---|
| CN (1) | CN115142995B (en) |
Citations (8)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| US5152273A (en) * | 1990-11-07 | 1992-10-06 | Mitsubishi Denki Kabushiki Kaisha | Exhaust gas recirculation control device and its failure diagnosis device |
| JPH06249081A (en) * | 1993-03-01 | 1994-09-06 | Mitsubishi Motors Corp | Method for judging failure in exhaust gas recirculating device |
| US5474051A (en) * | 1993-09-03 | 1995-12-12 | Mitsubishi Jidosha Kogyo Kabushiki Kaisha | Fault detection method and system for exhaust gas recirculation system |
| JP2013144961A (en) * | 2012-01-16 | 2013-07-25 | Hitachi Automotive Systems Ltd | Failure diagnostic device for egr system |
| JP2018123694A (en) * | 2017-01-30 | 2018-08-09 | 日立オートモティブシステムズ株式会社 | Fault diagnosis equipment for low pressure egr system |
| CN110486200A (en) * | 2019-09-11 | 2019-11-22 | 潍柴西港新能源动力有限公司 | Improved new-type EGR valve and its control method |
| DE102019220438A1 (en) * | 2019-12-20 | 2021-06-24 | Volkswagen Aktiengesellschaft | Diagnostic procedure for the detection of errors in an exhaust gas recirculation |
| CN113757000A (en) * | 2021-08-31 | 2021-12-07 | 联合汽车电子有限公司 | Detection method, device, equipment and storage medium of exhaust gas recirculation system |
Family Cites Families (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| DE102008041804B4 (en) * | 2008-09-04 | 2020-06-25 | Robert Bosch Gmbh | Method and device for monitoring an exhaust gas recirculation system |
-
2022
- 2022-07-13 CN CN202210824285.5A patent/CN115142995B/en active Active
Patent Citations (8)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| US5152273A (en) * | 1990-11-07 | 1992-10-06 | Mitsubishi Denki Kabushiki Kaisha | Exhaust gas recirculation control device and its failure diagnosis device |
| JPH06249081A (en) * | 1993-03-01 | 1994-09-06 | Mitsubishi Motors Corp | Method for judging failure in exhaust gas recirculating device |
| US5474051A (en) * | 1993-09-03 | 1995-12-12 | Mitsubishi Jidosha Kogyo Kabushiki Kaisha | Fault detection method and system for exhaust gas recirculation system |
| JP2013144961A (en) * | 2012-01-16 | 2013-07-25 | Hitachi Automotive Systems Ltd | Failure diagnostic device for egr system |
| JP2018123694A (en) * | 2017-01-30 | 2018-08-09 | 日立オートモティブシステムズ株式会社 | Fault diagnosis equipment for low pressure egr system |
| CN110486200A (en) * | 2019-09-11 | 2019-11-22 | 潍柴西港新能源动力有限公司 | Improved new-type EGR valve and its control method |
| DE102019220438A1 (en) * | 2019-12-20 | 2021-06-24 | Volkswagen Aktiengesellschaft | Diagnostic procedure for the detection of errors in an exhaust gas recirculation |
| CN113757000A (en) * | 2021-08-31 | 2021-12-07 | 联合汽车电子有限公司 | Detection method, device, equipment and storage medium of exhaust gas recirculation system |
Also Published As
| Publication number | Publication date |
|---|---|
| CN115142995A (en) | 2022-10-04 |
Similar Documents
| Publication | Publication Date | Title |
|---|---|---|
| CN113757000B (en) | Detection method, device, equipment and storage medium of exhaust gas recirculation system | |
| US6666201B1 (en) | System and method for diagnosing EGR performance using NOx sensor | |
| CN110925111B (en) | Throttle valve diagnosis method and device, control equipment and readable storage medium | |
| CN112983690B (en) | Flow diagnosis method and device of EGR (exhaust gas Recirculation) system and automobile | |
| WO2013175779A1 (en) | Fault detection method | |
| US20100307231A1 (en) | Method for diagnosing the bypass flap of an exchanger in an exhaust gas recirculation system | |
| JP2000213423A (en) | Egr fault diagnostic system | |
| KR101951619B1 (en) | Method for diagnosing a tank ventilation system | |
| KR101836285B1 (en) | Apparatus and method for dignozing failure of sensor | |
| US9534968B2 (en) | Fault detection method | |
| CN113219938B (en) | Flow diagnosis method and system for low-pressure EGR (exhaust gas Recirculation) system of gasoline engine and readable storage medium | |
| CN104040160A (en) | Method for specifying a malfunction of an exhaust gas recirculation system of a motor vehicle internal combustion engine, and corresponding diagnostic device | |
| EP2058493A1 (en) | A diagnostic method for a vehicle engine apparatus, provided with sensors | |
| JP5120333B2 (en) | Air flow meter failure diagnosis device | |
| RU2700175C2 (en) | Method for diagnosing motor vehicle partial exhaust gas recirculation system | |
| CN115142995B (en) | Method, device, system and storage medium for monitoring exhaust gas recirculation system | |
| US11492951B2 (en) | EGR effective flow diagnosis method | |
| CN113756999B (en) | EGR flow fault detection method and device | |
| CN111886552A (en) | Diagnostic system and method for isolating failure modes of a vehicle | |
| WO2018127598A1 (en) | Method to detect faults in boost system of a turbocharged engine | |
| JP7373380B2 (en) | Humidity sensor diagnostic device and humidity sensor diagnostic method | |
| CN111413100B (en) | Error reporting method and system for simulating exhaust gas circulation quantity abnormality of EGR (exhaust gas recirculation) system | |
| CN211477618U (en) | Device for simulating abnormity of fresh air inflow of diesel engine | |
| KR101806372B1 (en) | Diagnosis Method of the Relative Humidity Sensor for Vehicle | |
| KR102323409B1 (en) | Method and system for diagnosing boost pressure sensor |
Legal Events
| Date | Code | Title | Description |
|---|---|---|---|
| PB01 | Publication | ||
| PB01 | Publication | ||
| SE01 | Entry into force of request for substantive examination | ||
| SE01 | Entry into force of request for substantive examination | ||
| GR01 | Patent grant | ||
| GR01 | Patent grant |