CN115788669A - Crankcase ventilation system diagnosis method, device, equipment and storage medium - Google Patents
Crankcase ventilation system diagnosis method, device, equipment and storage medium Download PDFInfo
- Publication number
- CN115788669A CN115788669A CN202211343880.3A CN202211343880A CN115788669A CN 115788669 A CN115788669 A CN 115788669A CN 202211343880 A CN202211343880 A CN 202211343880A CN 115788669 A CN115788669 A CN 115788669A
- Authority
- CN
- China
- Prior art keywords
- air
- flow meter
- air leakage
- air inlet
- crankcase
- 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.)
- Granted
Links
- 238000009423 ventilation Methods 0.000 title claims abstract description 84
- 238000003745 diagnosis Methods 0.000 title claims abstract description 32
- 238000000034 method Methods 0.000 title claims abstract description 29
- 238000002405 diagnostic procedure Methods 0.000 claims description 13
- 239000003054 catalyst Substances 0.000 claims description 12
- 238000004590 computer program Methods 0.000 claims description 10
- 238000012545 processing Methods 0.000 claims description 7
- 238000004891 communication Methods 0.000 claims description 6
- 230000010354 integration Effects 0.000 claims description 6
- 238000001914 filtration Methods 0.000 claims description 5
- 238000012544 monitoring process Methods 0.000 abstract description 6
- OKTJSMMVPCPJKN-UHFFFAOYSA-N Carbon Chemical compound [C] OKTJSMMVPCPJKN-UHFFFAOYSA-N 0.000 description 9
- 229910052799 carbon Inorganic materials 0.000 description 9
- 238000010586 diagram Methods 0.000 description 6
- 230000008569 process Effects 0.000 description 6
- 230000006870 function Effects 0.000 description 4
- 230000000694 effects Effects 0.000 description 3
- 238000012360 testing method Methods 0.000 description 3
- 238000004364 calculation method Methods 0.000 description 2
- 239000000356 contaminant Substances 0.000 description 2
- 238000012986 modification Methods 0.000 description 2
- 230000004048 modification Effects 0.000 description 2
- 238000005070 sampling Methods 0.000 description 2
- 230000008859 change Effects 0.000 description 1
- 238000006243 chemical reaction Methods 0.000 description 1
- 238000002485 combustion reaction Methods 0.000 description 1
- 238000012937 correction Methods 0.000 description 1
- 230000001934 delay Effects 0.000 description 1
- 230000003111 delayed effect Effects 0.000 description 1
- 238000003795 desorption Methods 0.000 description 1
- 239000003344 environmental pollutant Substances 0.000 description 1
- 238000002474 experimental method Methods 0.000 description 1
- 230000006872 improvement Effects 0.000 description 1
- 238000005259 measurement Methods 0.000 description 1
- 231100000719 pollutant Toxicity 0.000 description 1
- 238000004064 recycling Methods 0.000 description 1
- 230000001052 transient effect Effects 0.000 description 1
- 230000000007 visual effect Effects 0.000 description 1
Images
Classifications
-
- 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
Landscapes
- Combined Controls Of Internal Combustion Engines (AREA)
Abstract
The invention provides a crankcase ventilation system diagnosis method, a device, equipment and a storage medium, and relates to the technical field of ventilation or air exchange of a crankcase. In the scheme, under the condition that a high-pressure end pipeline of a crankcase ventilation system cannot be hardware-exempted, the cost of newly adding a conductive PCV pipeline, a wire harness, ECU PIN resources and a special conductive quick connector for meeting the national six-regulation requirement can be avoided, and fault monitoring for identifying the dropping phenomenon of the PCV pipeline can be realized only through internal logic of an EMS system.
Description
Technical Field
The invention belongs to the technical field of ventilation or air exchange of a crankcase, and particularly relates to a diagnosis method, a diagnosis device, diagnosis equipment and a storage medium for a crankcase ventilation system.
Background
According to the requirements of J.4.9 in the discharge standard of the sixth stage of China (GB 18352.6-2016), the crankcase ventilation device of an automobile engine must adopt a closed structure in principle, and does not allow crankcase pollutants to be directly discharged into the atmosphere. In order to meet the requirements of legislation, crankcase contaminants are typically introduced into the air intake system from the cylinder head cover via a ventilation duct, and allowed to re-enter the cylinder for combustion. With this configuration, the ECU must have a corresponding OBD diagnostic strategy to ensure that when the crankcase ventilation duct is disconnected, causing direct discharge of crankcase contaminants into the atmosphere, the ECU diagnoses the disconnection fault in time and prompts the driver with a visual warning system.
The current OBD diagnosis strategy has two major trends, one is to carry out fault monitoring exemption from a hardware structure according to the J.4.9.2.3 requirement in the GB18352.6-2016 standard; the second is to adopt a diagnostic scheme based on electric circuit to realize fault monitoring, wherein, the patent: this is described in detail in an electrical circuit based engine crankcase ventilation OBD diagnostic method (CN 111765003A), which requires that the PCV line must be a conductive tube of an electrical circuit, the associated line connection must also be a conductive connection, and a corresponding Engine Controller (ECU) pin resource and harness are provided. The power assembly with the HFM can adopt a common plastic PCV pipeline, and whether the PCV pipeline falls off or not is identified by adopting an air leakage estimation and diagnosis mode of an air intake manifold model, so that the effect of reducing the cost is achieved.
Disclosure of Invention
The purpose of the invention is: aims to provide a diagnosis method, a device, equipment and a storage medium for a crankcase ventilation system, which are used for solving the problem that the cost is higher because related pipelines in the existing diagnosis method for the crankcase ventilation system of an engine are conductive pipelines and are provided with corresponding pin resources
In order to achieve the technical purpose, the technical scheme adopted by the invention is as follows:
in a first aspect, an embodiment of the present application provides a diagnostic method for a crankcase ventilation system, which is applied to a diagnostic device, where the diagnostic device includes a first flow meter, a second flow meter, a ventilation pipeline, an air inlet channel, a crankcase, and an air cleaner, where the crankcase includes an intake manifold, the air cleaner is based on the air inlet channel and the intake manifold, the first flow meter is disposed on the air inlet channel, the second flow meter is disposed in the crankcase intake manifold, one end of the ventilation pipeline is connected to the air inlet channel, and the other end of the ventilation pipeline is connected to the crankcase, where the ventilation pipeline is located at a connection position of the air inlet channel between the first flow meter and the intake manifold, the diagnostic method includes the following steps:
s1: acquiring real-time air inflow input into the air inlet channel by the air filter and theoretical model air inflow acquired from the air inlet channel by the air inlet manifold on the basis of the first flowmeter and the second flowmeter;
s2: estimating the air leakage of the ventilation pipeline based on the real-time air inflow and the theoretical model air inflow, and obtaining equivalent air leakage based on the air leakage when the air leakage reaches an initial calibration threshold value;
s3: and judging whether the equivalent air leakage reaches a terminal calibration threshold value or not, and selecting corresponding fault management logic based on a judgment result to finish diagnosis.
With reference to the first aspect, in some optional embodiments, the diagnostic apparatus further includes a canister solenoid valve and a brake auxiliary vacuum pump in communication with the intake manifold, an exhaust manifold and a catalyst, the exhaust manifold is in communication with the catalyst based on a pipeline, an EGR valve is further disposed on the pipeline between the exhaust manifold and the catalyst, the apparatus further includes a controller electrically connected to the first flow meter and the second flow meter, respectively, and before the real-time intake air amount and the theoretical model intake air amount are obtained based on the first flow meter and the second flow meter, the apparatus further includes the following steps:
closing the canister solenoid valve, the brake assist vacuum pump, and the EGR valve.
With reference to the first aspect, in some optional embodiments, the air leakage of the ventilation pipeline is estimated by:
obtaining the difference value between the real-time air inflow and the theoretical model air inflow, and obtaining the air leakage after low-pass filtering the difference value,
with reference to the first aspect, in some optional embodiments, obtaining the equivalent air leakage based on the air leakage comprises: and correcting the air leakage based on integration to obtain the equivalent air leakage, so that the discrimination of the air leakage when the pressure of the intake manifold is higher can be increased based on the deviation integration of the air leakage under the condition that the air leakage is smaller in value due to the higher pressure of the intake manifold.
With reference to the first aspect, in some optional embodiments, when the equivalent air leakage does not reach the end calibration threshold, a failure-free report is presented; and when the equivalent air leakage reaches the tail end calibration threshold value, judging that the ventilation pipeline leaks air, and reporting a fault.
In a second aspect, an embodiment of the present application further provides a diagnostic apparatus for a crankcase ventilation system, which is applied to a diagnostic device, the diagnostic device includes a first flow meter, a second flow meter, a ventilation pipeline, an air inlet channel, a crankcase and an air cleaner, the crankcase includes an air inlet manifold, the air cleaner is based on the air inlet channel and the air inlet manifold UNICOM, the first flow meter is disposed on the air inlet channel, the second flow meter is disposed in the crankcase air inlet manifold, one end of the ventilation pipeline is connected to the air inlet channel, the other end is connected to the crankcase, wherein the ventilation pipeline is located at a connection position of the air inlet channel between the first flow meter and the air inlet manifold, the diagnostic apparatus includes:
the acquisition unit is used for acquiring the real-time air inflow input into the air inlet channel by the air filter and the theoretical model air inflow acquired from the air inlet channel by the air inlet manifold based on the first flowmeter and the second flowmeter;
the processing unit is used for estimating the air leakage of the ventilation pipeline based on the real-time air inflow and the theoretical model air inflow and acquiring equivalent air leakage based on the air leakage when the air leakage reaches an initial calibration threshold value;
and the selection unit is used for judging whether the equivalent air leakage reaches a terminal calibration threshold value or not, selecting corresponding fault management logic based on a judgment result and finishing diagnosis.
With reference to the second aspect, in some optional embodiments, the diagnostic apparatus further includes a canister solenoid valve and a brake-assisted vacuum pump in communication with the intake manifold, an exhaust manifold in communication with the catalyst based on a conduit, an EGR valve further disposed on the conduit between the exhaust manifold and the catalyst, a controller electrically connected to the first flow meter and the second flow meter, respectively, the diagnostic apparatus further includes:
and the switching unit controls to close the carbon tank electromagnetic valve, the brake auxiliary vacuum pump and the EGR valve before the first flow meter and the second flow meter acquire the flow.
With reference to the second aspect, in some optional embodiments, the acquisition unit, the processing unit and the selection unit are respectively coupled to the controller, and the switch unit is coupled to the controller.
In a third aspect, an embodiment of the present application further provides a diagnostic apparatus for a crankcase ventilation system, the diagnostic apparatus includes a first flow meter, a second flow meter, a ventilation pipeline, an air inlet channel, a crankcase, an air cleaner, and a storage module, the crankcase includes an intake manifold, the air cleaner is based on the air inlet channel and the intake manifold, the first flow meter is disposed on the air inlet channel, the second flow meter is disposed in the crankcase intake manifold, one end of the ventilation pipeline is connected to the air inlet channel, and the other end of the ventilation pipeline is connected to the crankcase, wherein the connection between the ventilation pipeline and the air inlet channel is located between the first flow meter and the intake manifold, the storage module stores a computer program, and when the computer program is executed by the controller, the diagnostic apparatus executes the method described above.
In a fourth aspect, an embodiment of the present invention further provides a computer-readable storage medium, where a computer program is stored in the computer-readable storage medium, and when the computer program runs on a computer, the computer is caused to execute the above method.
The invention adopting the technical scheme has the advantages that:
the embodiment of the application provides a diagnostic method, a diagnostic device, equipment and a storage medium for a crankcase ventilation system. Under the condition that a high-pressure end pipeline of a crankcase ventilation system cannot be hardware-exempted, the cost of newly adding a conductive PCV pipeline, a wire harness, ECU PIN resources and a special conductive quick connector for meeting the national six-regulation requirement can be avoided, and fault monitoring for identifying the PCV pipeline falling-off phenomenon is achieved only through internal logic of an EMS system. The invention is also applicable to hybrid systems with HFM.
Drawings
The invention is further illustrated by the non-limiting examples given in the accompanying drawings;
FIG. 1 is a schematic flow diagram of a crankcase ventilation system diagnostic method of the present invention;
FIG. 2 is a schematic view of the connection of the diagnostic device for a crankcase ventilation system of the present invention;
FIG. 3 is a schematic view of the crankcase ventilation system diagnostic device of the present invention;
FIG. 4 is a strategy flow diagram of a crankcase ventilation system diagnostic method of the present invention;
the main element symbols are as follows:
1: a first flow meter; 2: a second flow meter; 3: a ventilation line; 4: an air inlet channel; 5: an intake manifold; 6: an air cleaner; 7: a canister solenoid valve; 8: braking an auxiliary vacuum pump; 9: an exhaust manifold; 10: a catalyst; 11: an EGR valve; 12: a collection unit; 13: a processing unit; 14: a controller; 15: a selection unit; 16: a switch unit.
Detailed Description
The present invention will be described in detail with reference to the drawings and specific embodiments, wherein like reference numerals are used for similar or identical parts in the drawings or the description, and implementations not shown or described in the drawings are known to those of ordinary skill in the art. In addition, directional terms, such as "upper", "lower", "top", "bottom", "left", "right", "front", "rear", and the like, used in the embodiments are only directions referring to the drawings, and are not intended to limit the scope of the present invention.
As shown in fig. 2, the present invention provides a diagnostic apparatus for a crankcase ventilation system, which includes a first flow meter 1, a second flow meter 2, a ventilation pipeline 3, an air inlet passage 4, a crankcase and air filter 6, an air inlet manifold 5, and a storage module. The air cleaner 6 communicates with the intake manifold 5 based on the intake passage 4. The first flow meter 1 is provided on the intake passage 4. The second flow meter 2 is arranged in the crankcase intake manifold 5. One end of the ventilation pipeline 3 is connected with the air inlet channel 4, and the other end of the ventilation pipeline is connected with the crankcase. Wherein, the joint of the ventilation pipeline 3 and the air inlet channel 4 is positioned between the first flowmeter 1 and the air inlet manifold 5. The diagnostic equipment further comprises a carbon tank electromagnetic valve 7 communicated with the air inlet manifold 5, a brake auxiliary vacuum pump 8, an exhaust manifold 9 and a catalyst 10, wherein the exhaust manifold 8 is communicated with the catalyst 10 on the basis of a pipeline, an EGR valve 11 is further arranged on the pipeline between the exhaust manifold 8 and the catalyst 10, the equipment further comprises a controller 14, and the controller 14 is electrically connected with the first flowmeter 1 and the second flowmeter 2 respectively.
The first flow meter 1 is used to collect the real time intake air amount into the crankcase through the air cleaner 6. The first flow meter may be an HFM (air flow meter) in this application, and is capable of collecting real-time intake air amount and transmitting it to the controller 14. The second flowmeter 2 is used for collecting theoretical model air inflow actually entered by an intake manifold 5, namely, part of air in a crankcase comes from real-time air inflow with an air filter 6, and part of air flows into an air inlet channel 4 from the direction of a ventilation pipeline 3 when the ventilation pipeline 3 leaks or falls off, wherein when the ventilation pipeline 3 leaks, due to the pressure drop effect of the air filter 6, the air pressure of the air inlet channel 4 is slightly lower than the atmospheric pressure, and partial air flows into the air inlet channel 4 at a first joint or a second joint. It should be noted that, in a normal state, a part of the gas in the ventilation pipeline 3 flows into the intake passage 4 from the crankcase, but the process is negligible compared to the process described later in the present application, when the first joint or the second joint generates the dropping gas leakage, the gas flowing into the intake passage 4 from the first joint can be defined as the gas leakage. The second flow meter 2 may be a MAP (pressure sensor) for deriving a theoretical model intake air amount in the intake manifold 5 based on the collected pressure.
Conventional components such as a supercharger, a throttle valve and the like are further arranged on the air inlet channel 4, and redundant description is omitted, it is to be noted that in the conventional arrangement of the vehicle, the air inlet manifold 5 is further communicated with the carbon canister electromagnetic valve 7 and the brake auxiliary vacuum pump 8, wherein the brake auxiliary vacuum pump 8 is used for auxiliary braking during mechanical braking, and in order to ensure the simplicity of gas sources in the air inlet manifold 5, the carbon canister electromagnetic valve 7, the brake auxiliary vacuum pump 8 and the EGR valve 11 need to be closed before diagnosis, and the EGR valve 11 can be closed and can also be maintained at a certain opening degree (detailed description later)
The controller 14 is used for recording the ambient temperature, the atmospheric pressure and the engine speed, the load, the canister solenoid valve operating state, the EGR opening degree, and the vehicle brake pedal operating state in real time, and preferably, the controller 14 may be an EMS system (engine management system).
The EGR valve 11 is used for being connected with LP-EGR (low pressure exhaust gas in circulation system) for delivering a part of low pressure exhaust gas to the intake passage 4 for recycling, and in order to ensure the gas source unicity in the intake manifold 9 at the time of diagnosis, the EGR valve 11 needs to be kept closed or maintained at a desired opening degree when diagnosing whether the ventilation pipeline 3 is dropped or leaked.
It should be noted that the crankcase may also communicate with the intake manifold 5 through the PCV low pressure section line, and in order to prevent the gas in the crankcase from affecting the acquisition of the theoretical model intake air amount in the intake manifold 5, only diagnosis when the ventilation line 3 (i.e. the PCV high pressure end line) is disconnected at a high pressure is considered in the present application, and no gas or only a small amount of gas does not affect the flow of the whole gas flow in the PCV low pressure end line.
The storage module stores therein a computer program which, when executed by the controller 14, enables the diagnostic device to perform the respective steps of the diagnostic method described below.
Referring to fig. 1 and 4, the present application further provides a diagnostic method for a crankcase ventilation system. The diagnostic method may include the steps of:
s1: acquiring real-time air inlet amount input into the air inlet channel 4 by the air filter 6 and theoretical model air inlet amount acquired from the air inlet channel 4 by the air inlet manifold 5 based on the first flow meter 1 and the second flow meter 2;
s2: estimating the air leakage of the ventilation pipeline 3 based on the real-time air inflow and the theoretical model air inflow, and obtaining equivalent air leakage based on the air leakage when the air leakage reaches an initial calibration threshold value;
s3: and judging whether the equivalent air leakage reaches a terminal calibration threshold value or not, selecting corresponding fault management logic based on a judgment result, and finishing diagnosis.
The steps of the crankcase ventilation system diagnostic method will be described in detail below, as follows:
it should be noted that, in the present invention, when there is a large pressure fluctuation in the system or there is an unreliability that the deviation of the system air leakage becomes after the gas that does not pass through the first flow meter 1 enters the intake manifold 5, it is necessary to consider limiting the following cases to improve the diagnostic reliability:
1) The EGR valve is opened too much or the EGR works unstably or the deviation of the flow of the EGR valve is too large.
2) The brake vacuum pump is operated during diagnostics (only the arrangement of the vacuum source from the intake manifold is considered).
3) And the carbon tank electromagnetic valve is opened, the carbon tank is desorbed and activated, and the carbon tank flow estimation is not accurate.
4) The PCV high-pressure end interface is small, so that the air leakage of the interface is not obvious after the joint 1 falls off, and the pipe diameter of a pipeline or the caliber of the joint can be properly increased.
Therefore, before step S1, the following steps need to be completed:
and (4) judging the diagnosis enabling working condition, wherein the controller 14 records the ambient temperature, the atmospheric pressure, the engine rotating speed, the load, the working state of the carbon canister electromagnetic valve, the EGR opening degree and the working state of a brake pedal of the whole vehicle in real time in the running process of the engine. The controller 14 determines whether the conditions for enabling the operating condition are satisfied:
the first condition is as follows: the ambient temperature is-7 to 35 ℃ and the atmospheric pressure is higher than 70Kpa in the running process of the engine;
and a second condition: the opening of the EGR valve 11 is below a calibrated threshold: 5 percent;
and (3) carrying out a third condition: engine load less than calibration: 25. and the rate of change of engine load is less than a calibration threshold: 5 percent;
and a fourth condition: the engine speed is less than the calibration value: 1500. and the fluctuation of the engine speed is less than 5% of the calibration threshold value;
and a fifth condition: the brake pedal does not work or delays for 5s after working;
and a sixth condition: the controller 14 does not monitor for the presence of any of the following faults
1. The first flow meter 1 drives the stage and rationality failure.
2. The second flow meter 2 drives the stage and rationality failure.
3. Driving stage and rationality failure of related components of a supercharging system
4. Throttle drive stage and rationality failure
5. The driving stage of the carbon canister electromagnetic valve 7 is in normally open failure with clamping stagnation.
6. PCV Low pressure end shedding fault (high idle speed)
Note: drive level faults include short-to-power faults, short-to-ground faults, open faults of the sensor or drive component. The rationality faults include signal jamming of Pin pins of the sensor or the driving component, signal out-of-range and unreasonable signal jump faults.
After the six conditions are all met, the ventilation pipeline 3 (PCV high-pressure end pipeline) is enabled to be activated in the falling diagnosis mode, and if any condition is not met, the diagnosis enabling working condition is reset to be judged.
In step S1, the method of estimating the theoretical model intake air amount of the intake manifold 5 using the second flowmeter 2 needs calibration by bench test, and calibration parameters of the conversion are given in advance by checking the ideal gas state formula (PV = nRT). Aiming at the engine of the hybrid power system, the calibration range of the bench test needs to be properly expanded. The first joint and the second joint operating mode when droing need be considered respectively during the experiment, specifically need to contain as follows:
1) Under the normal state: the pressure of the intake manifold 5 corresponding to 700-1500RPM, the theoretical model air inflow estimated based on the pressure of the intake manifold 5, the real-time air inflow actually measured by the first flowmeter 1, and the pressure (equal gradient) of the intake manifold 5 estimated based on the real-time air inflow.
2) Disconnect the second joint (crankcase end) of the ventilation line: the pressure of the intake manifold 1 corresponding to 700-1500RPM, the theoretical model air inflow estimated based on the pressure of the intake manifold 1, the real-time air inflow actually measured by the first flowmeter 1 and the pressure of the intake manifold 5 estimated based on the real-time air inflow.
3) Disconnect the first connection (air filter end) of the ventilation line: the pressure of the intake manifold 1 corresponding to 700-1500RPM, the theoretical model air inflow estimated based on the pressure of the intake manifold 1, the real-time air inflow actually measured by the first flow meter 1 and the pressure of the intake manifold 5 estimated based on the real-time air inflow.
And confirming effective difference of the predicted intake air flow based on the manifold pressure in 1) and 2) and 3) through the bench data, adjusting reference and threshold division for a subsequent air leakage integral coefficient, and synchronously confirming the most reliable rotating speed-load diagnosis area.
Confirming the estimated theoretical model air input through table lookup:
horizontal axis: pressure array based on intake manifold 1
For example, intake manifold pressure [30,40,50,60,70,80,110], in Kpa;
and (3) checking the standard value: estimating the air input of the theoretical model based on the pressure of the intake manifold;
for example, an inlet flow rate [1.9,2.5,3,4,6,8, 15] may be estimated in g/s.
Based on the temperature of the intake manifold 5, appropriate correction of the estimated intake air flow rate is required, and this coefficient can be calibrated.
After the diagnostic enable is activated, the controller 14 requests to stop the canister solenoid valve 7 desorption, and when the canister solenoid valve 7 is closed, the internal diagnostic routine activates the relevant data sampling. The method specifically comprises the following sampling data:
firstly, the following steps: real-time air inflow (A1) measured by a first flow meter 1;
II, secondly: the theoretical model intake air amount (A2) calculated based on the second flow meter 2.
In step S2, the air leakage of the ventilation pipeline 3 is estimated based on the real-time air input and the theoretical model air input, and an equivalent air leakage is obtained based on the air leakage when the air leakage reaches an initial calibration threshold. That is, the air leakage amount at the drop position of the ventilation pipe 3 is estimated by the difference between (A1) and (A2) (A3). Theoretically, the difference value between the theoretical model air inflow calculated based on the second flowmeter 2 and the actual air inflow actually measured by the first flowmeter 1 is the air leakage amount dropped out from the ventilation pipeline 3. It should be noted that the A3 needs to be considered to be subjected to low-pass filtering and then participate in subsequent calculation to eliminate the misjudgment phenomenon caused by the large pressure deviation of the transient state, and the filtering formula is recommended as follows:
a3 (new) = A3 (old) + [ in-A3 (old) ] -dT × K1, where in = A2-A1, dT is the present logic operation period, and K1 reflects the filtering speed.
Generally, in the case where no PCV line falls off, A3 fluctuates in a small range around 0; when the ventilation pipeline 3 falls off, due to the pressure drop effect of the air filter 6, the air pressure of the air inlet channel 4 behind the first flow meter 1 is slightly lower than the atmospheric pressure, which causes a part of air to flow into the air inlet channel at the first joint or the second joint, and causes the deviation of the air flow finally entering the air inlet manifold 5 and the air inlet flow measured by the first flow meter 1, namely, A3 deviates from the vicinity of 0.
Through actual bench measurement, the air leakage A3 is proportional to the joint aperture of the ventilation pipe 3 and inversely proportional to the pressure of the ventilation pipe 3. Generally, the air leakage amount after the ventilation pipeline 3 falls off is most remarkable under the idling condition.
When the controller 14 monitors that | A3| is smaller than the initial calibration threshold value (2 g/s), it indicates that the theoretical model air inflow is equivalent to the measured air inflow, and no air leakage phenomenon exists, and after the calibration time is delayed for 3s, the fast pass (Fastpass) is diagnosed.
When | A3| is greater than the initial calibration threshold value (2 g/s), a virtual equivalent air leakage (A4) is calculated according to the following formula:
the time t can be calibrated according to the duration of the average steady state area of the power assembly in the WLTC, the integration coefficient K2 can adjust the speed of integration, and the comprehensive calibration is carried out according to the requirement of the fault reporting time. The applicability of the logic can be enhanced by correcting the equivalent air leakage in an integral mode. When the air leakage phenomenon is amplified in a mode of integrating air volume deviation under the condition that the whole A3 is low due to phenomena of high pressure of the intake manifold 5 and the like in a steady state, the discrimination between the air leakage phenomenon and the normal state is increased.
In step S3, it is determined whether the equivalent air leakage reaches a terminal calibration threshold, and a corresponding fault management logic is selected based on the determination result, thereby completing the diagnosis. When FastPass logic is satisfied, the diagnosis will pass quickly, the diagnosis is complete, and no fault is reported. FastPass effectively improves the diagnosis completion speed under normal working conditions and effectively improves the in-use monitoring frequency (IUPR).
And when the A4 reaches or exceeds the tail end calibration threshold value, the controller 14 judges that the ventilation pipeline 3 falling fault exists, the diagnosis is finished, and the fault is reported. The system stores fault codes, lights the MIL lamp and stores frozen frames according to the requirements of the regulations, and diagnosis is finished after the IUPR molecules grow. It is proposed that the diagnostic strategy allows for a number of attempts in the same driving cycle, which can be calibrated. Once the diagnosis is over, no further attempts are made in the current driving cycle.
The final calibration threshold value needs to consider the situation that the first joint and the second joint fall off respectively, and needs to consider a mode with least obvious air leakage as the basis of the calibration test division threshold value.
With continued reference to fig. 2 and 3, the present application also provides a diagnostic device for a crankcase ventilation System, which includes at least one software function module that can be stored in a memory module in the form of software or Firmware (Firmware) or solidified in an Operating System (OS) of the diagnostic apparatus. The controller 14 is used for executing executable modules stored in the storage module, such as software functional modules and computer programs included in the diagnostic apparatus.
The diagnostic device comprises an acquisition unit 12, a processing unit 13 and a selection unit 15, each unit having the following functions:
the acquisition unit 12 is used for acquiring the real-time air inflow input into the air inlet channel 4 by the air filter 6 and the theoretical model air inflow acquired from the air inlet channel 4 by the air inlet manifold 5 based on the first flowmeter 1 and the second flowmeter 2;
the processing unit 13 is used for estimating the air leakage of the ventilation pipeline 3 based on the real-time air inflow and the theoretical model air inflow and acquiring equivalent air leakage based on the air leakage when the air leakage reaches an initial calibration threshold value;
and the selecting unit 15 is used for judging whether the equivalent air leakage reaches a terminal calibration threshold value or not, selecting corresponding fault management logic based on a judgment result and finishing diagnosis.
Optionally, the diagnostic device may further comprise a switching unit 16. The switching unit 16 is used to close the canister solenoid valve 7, the brake assist vacuum pump 8 and the EGR valve 11 before the first flow meter 1 and the second flow meter pick up the respective gas flows. The switching unit 16 can close the gas line that may affect or make an error in the theoretical model intake air amount calculation in the intake manifold 5 before the diagnosis is started, ensuring the accuracy of the gas source in the intake manifold 5.
In this embodiment, the storage module may be, but is not limited to, a random access memory, a read only memory, a programmable read only memory, an erasable programmable read only memory, an electrically erasable programmable read only memory, and the like. In this embodiment, the storage module may be configured to store the collected data of the first flow meter 1 and the second flow meter 2, the initial calibration threshold value, the terminal calibration threshold value, and the like. Of course, the memory module may also be used to store a program that is executed by the controller 14 upon receiving an execution instruction.
It will be appreciated that the diagnostic device configuration shown in fig. 1 and 2 is merely a schematic configuration and that the diagnostic device may also include more components than those shown. The components shown in the figures may be implemented in hardware, software, or a combination thereof.
It should be noted that, for convenience and simplicity of description, it is clear to those skilled in the art that the specific working processes of the diagnostic apparatus and the diagnostic device described above may refer to the corresponding processes of the steps in the foregoing method, and redundant description is not repeated here.
The embodiment of the application also provides a computer readable storage medium. The computer-readable storage medium has stored therein a computer program which, when run on a computer, causes the computer to execute the ventilation system diagnosis method as described in the above-described embodiments.
From the above description of the embodiments, it is clear to those skilled in the art that the present application can be implemented by hardware, or by software plus a necessary general hardware platform, and based on such understanding, the technical solution of the present application can be embodied in the form of a software product, which can be stored in a non-volatile storage medium (which can be a CD-ROM, a usb disk, a removable hard disk, etc.), and includes several instructions to enable a computer device (which can be a personal computer, a diagnostic device, or a network device, etc.) to execute the method described in the embodiments of the present application.
In summary, the embodiments of the present application provide a method, an apparatus, a device and a storage medium for diagnosing a crankcase ventilation system. In the scheme, under the condition that a high-pressure end pipeline of a crankcase ventilation system cannot be hardware-exempted, the cost of a conductive PCV pipeline, a wire harness, an ECU PIN resource and a special conductive quick connector can not be increased for meeting the national six-regulation requirement, and fault monitoring for identifying the PCV pipeline falling-off phenomenon is achieved only through internal logic of an EMS system. The invention is also applicable to hybrid systems with HFM.
In the embodiments provided in the present application, it should be understood that the disclosed apparatus, system, and method may be implemented in other ways. The apparatus, system, and method embodiments described above are illustrative only, as the flowcharts and block diagrams in the figures illustrate the architecture, functionality, and operation of possible implementations of systems, methods and computer program products according to various embodiments of the present application. In this regard, each block in the flowchart or block diagrams may represent a module, segment, or portion of code, which comprises one or more executable instructions for implementing the specified logical function(s). It will also be noted that each block of the block diagrams and/or flowchart illustration, and combinations of blocks in the block diagrams and/or flowchart illustration, can be implemented by special purpose hardware-based systems which perform the specified functions or acts, or combinations of special purpose hardware and computer instructions. In addition, functional modules in the embodiments of the present application may be integrated together to form an independent part, or each module may exist separately, or two or more modules may be integrated to form an independent part.
The above description is only an example of the present application and is not intended to limit the scope of the present application, and various modifications and changes may be made by those skilled in the art. Any modification, equivalent replacement, improvement and the like made within the spirit and principle of the present application shall be included in the protection scope of the present application.
Claims (10)
1. A method for diagnosing a crankcase ventilation system, the method being applied to a diagnostic device, the diagnostic device comprising a first flow meter (1), a second flow meter (2), a ventilation pipeline (3), an air inlet (4), a crankcase, an air filter (6), and an air inlet manifold (5), wherein the air filter (6) is based on the air inlet (4) communicating with the air inlet manifold (5), the first flow meter (1) is disposed on the air inlet (4), the second flow meter (2) is disposed in the crankcase air inlet manifold (5), one end of the ventilation pipeline (3) is connected to the air inlet (4), and the other end of the ventilation pipeline is connected to the crankcase, wherein the connection between the ventilation pipeline (3) and the air inlet (4) is located between the first flow meter (1) and the air inlet manifold (5), the method comprising the steps of:
s1: acquiring real-time air inflow input into the air inlet channel (4) by the air filter (6) and theoretical model air inflow acquired from the air inlet channel (4) by the air manifold (5) based on the first flow meter (1) and the second flow meter (2);
s2: estimating the air leakage of the ventilation pipeline (3) based on the real-time air inflow and the theoretical model air inflow, and acquiring equivalent air leakage based on the air leakage when the air leakage reaches an initial calibration threshold value;
s3: and judging whether the equivalent air leakage reaches a terminal calibration threshold value or not and selecting corresponding fault management logic based on a judgment result.
2. The crankcase ventilation system diagnosis method according to claim 1, wherein the diagnosis apparatus further comprises a canister solenoid valve (7) and a brake auxiliary vacuum pump (8) in communication with the intake manifold (5), an exhaust manifold (9) and a catalyst (10), the exhaust manifold (9) is in communication with the catalyst (10) on the basis of a pipe, an EGR valve (11) is further provided on a pipe between the exhaust manifold (9) and the catalyst (10), the apparatus further comprises a controller (14), the controller (14) is electrically connected to the first flow meter (1) and the second flow meter (2), respectively, and further comprises the steps of, before obtaining the real-time intake air amount and the theoretical model based on the first flow meter (1) and the second flow meter (2):
closing the canister solenoid valve (7), the brake auxiliary vacuum pump (8) and the EGR valve (11).
3. The crankcase ventilation system diagnostic method according to claim 2, wherein estimating the amount of air leakage of the ventilation conduit (3) consists in:
and obtaining the difference value between the real-time air inflow and the theoretical model air inflow, and obtaining the air leakage after low-pass filtering the difference value.
4. The crankcase ventilation system diagnostic method of claim 3, wherein obtaining an equivalent air leakage based on the air leakage comprises: and correcting the air leakage based on integration to obtain the equivalent air leakage, so that under the condition that the air leakage value is smaller due to the fact that the pressure of the intake manifold (5) is higher, the discrimination of the air leakage when the pressure of the intake manifold (5) is higher can be increased based on the integration of the air leakage deviation.
5. The crankcase ventilation system diagnostic method of claim 4, wherein no fault is presented when the equivalent air leakage does not reach the terminal calibration threshold; and when the equivalent air leakage amount reaches the tail end calibration threshold value, judging that air leakage occurs in the ventilation pipeline (3), and reporting a fault.
6. A diagnostic device for a crankcase ventilation system, applied to the diagnostic apparatus according to claim 2, the diagnostic device comprising:
the acquisition unit (12) is used for acquiring real-time air inflow input into the air inlet channel (4) by the air filter (6) and theoretical model air inflow acquired from the air inlet channel (4) by the air intake manifold (5) based on the first flowmeter (1) and the second flowmeter (2);
the processing unit (13) estimates the air leakage of the ventilation pipeline (3) based on the real-time air inflow and the theoretical model air inflow and obtains the equivalent air leakage based on the air leakage when the air leakage reaches an initial calibration threshold value;
and the selection unit (15) is used for judging whether the equivalent air leakage reaches a tail end calibration threshold value or not and selecting corresponding fault management logic based on a judgment result.
7. The crankcase ventilation system diagnostic device of claim 6, further comprising:
a switching unit (16) that controls the canister solenoid valve (7), the brake assist vacuum pump (8), and the EGR valve (11) to be closed before the first flow meter (1) and the second flow meter (2) are sampled.
8. The crankcase ventilation system diagnostic device according to claim 7, wherein the acquisition unit (12), the processing unit (13) and the selection unit (15) are respectively coupled to the controller (14), and the switch unit (16) is coupled to the controller (14).
9. A diagnostic apparatus as claimed in claim 1, characterized in that the diagnostic apparatus further comprises a storage module in which a computer program is stored which, when executed by the controller (14), causes the diagnostic apparatus to carry out the method as claimed in any one of claims 1 to 5.
10. A computer-readable storage medium, in which a computer program is stored which, when run on a computer, causes the computer to carry out the method according to any one of claims 1-5.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN202211343880.3A CN115788669B (en) | 2022-10-31 | 2022-10-31 | Crankcase ventilation system diagnosis method, device, equipment and storage medium |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN202211343880.3A CN115788669B (en) | 2022-10-31 | 2022-10-31 | Crankcase ventilation system diagnosis method, device, equipment and storage medium |
Publications (2)
| Publication Number | Publication Date |
|---|---|
| CN115788669A true CN115788669A (en) | 2023-03-14 |
| CN115788669B CN115788669B (en) | 2024-05-03 |
Family
ID=85434463
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CN202211343880.3A Active CN115788669B (en) | 2022-10-31 | 2022-10-31 | Crankcase ventilation system diagnosis method, device, equipment and storage medium |
Country Status (1)
| Country | Link |
|---|---|
| CN (1) | CN115788669B (en) |
Citations (13)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JPH04314928A (en) * | 1990-12-20 | 1992-11-06 | Robert Bosch Gmbh | Tank ventilator and method of inspecting airtightness thereof |
| US20050022795A1 (en) * | 2003-05-06 | 2005-02-03 | Hans-Ernst Beyer | Method and device for operating an internal combustion engine |
| KR20120074034A (en) * | 2010-12-27 | 2012-07-05 | 주식회사 포스코 | Method for correcting injection amount of a pulverized coal into blow furnace |
| US20150121864A1 (en) * | 2013-11-06 | 2015-05-07 | Ford Global Technologies, Llc | Methods and systems for pcv flow estimation with an intake oxygen sensor |
| US20170002776A1 (en) * | 2015-06-30 | 2017-01-05 | Ford Global Technologies, Llc | Positive crankcase ventilation (pcv) device and engine assembly employing the same |
| CN111075534A (en) * | 2019-12-24 | 2020-04-28 | 中国第一汽车股份有限公司 | Crankcase ventilation system and integrity detection method thereof |
| US10767590B1 (en) * | 2019-06-24 | 2020-09-08 | Ford Global Technologies, Llc | Crankcase ventilation system and diagnostic method |
| CN111852653A (en) * | 2019-04-24 | 2020-10-30 | 联合汽车电子有限公司 | Diagnostic device and diagnostic method for crankcase ventilation pipeline |
| CN113107673A (en) * | 2020-01-13 | 2021-07-13 | 上海汽车集团股份有限公司 | Pipeline disconnection diagnosis method and device and electronic equipment |
| CN113404593A (en) * | 2020-03-16 | 2021-09-17 | 长城汽车股份有限公司 | Diagnosis method and device |
| CN114483254A (en) * | 2020-11-11 | 2022-05-13 | 长城汽车股份有限公司 | Processing method for ventilation blockage fault of crankcase and terminal equipment |
| CN114837769A (en) * | 2022-05-31 | 2022-08-02 | 岚图汽车科技有限公司 | Crankcase ventilation pipe icing verification method, device, equipment and storage medium |
| CN114839131A (en) * | 2022-05-23 | 2022-08-02 | 上海弗列加滤清器有限公司 | Testing device and testing method for performance of ventilation filter of crankcase |
-
2022
- 2022-10-31 CN CN202211343880.3A patent/CN115788669B/en active Active
Patent Citations (13)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JPH04314928A (en) * | 1990-12-20 | 1992-11-06 | Robert Bosch Gmbh | Tank ventilator and method of inspecting airtightness thereof |
| US20050022795A1 (en) * | 2003-05-06 | 2005-02-03 | Hans-Ernst Beyer | Method and device for operating an internal combustion engine |
| KR20120074034A (en) * | 2010-12-27 | 2012-07-05 | 주식회사 포스코 | Method for correcting injection amount of a pulverized coal into blow furnace |
| US20150121864A1 (en) * | 2013-11-06 | 2015-05-07 | Ford Global Technologies, Llc | Methods and systems for pcv flow estimation with an intake oxygen sensor |
| US20170002776A1 (en) * | 2015-06-30 | 2017-01-05 | Ford Global Technologies, Llc | Positive crankcase ventilation (pcv) device and engine assembly employing the same |
| CN111852653A (en) * | 2019-04-24 | 2020-10-30 | 联合汽车电子有限公司 | Diagnostic device and diagnostic method for crankcase ventilation pipeline |
| US10767590B1 (en) * | 2019-06-24 | 2020-09-08 | Ford Global Technologies, Llc | Crankcase ventilation system and diagnostic method |
| CN111075534A (en) * | 2019-12-24 | 2020-04-28 | 中国第一汽车股份有限公司 | Crankcase ventilation system and integrity detection method thereof |
| CN113107673A (en) * | 2020-01-13 | 2021-07-13 | 上海汽车集团股份有限公司 | Pipeline disconnection diagnosis method and device and electronic equipment |
| CN113404593A (en) * | 2020-03-16 | 2021-09-17 | 长城汽车股份有限公司 | Diagnosis method and device |
| CN114483254A (en) * | 2020-11-11 | 2022-05-13 | 长城汽车股份有限公司 | Processing method for ventilation blockage fault of crankcase and terminal equipment |
| CN114839131A (en) * | 2022-05-23 | 2022-08-02 | 上海弗列加滤清器有限公司 | Testing device and testing method for performance of ventilation filter of crankcase |
| CN114837769A (en) * | 2022-05-31 | 2022-08-02 | 岚图汽车科技有限公司 | Crankcase ventilation pipe icing verification method, device, equipment and storage medium |
Non-Patent Citations (1)
| Title |
|---|
| 李军;饶均;田延庆;张世艺;: "发动机进气歧管稳压腔结构优化", 计算机仿真, no. 08, 15 August 2016 (2016-08-15), pages 158 - 162 * |
Also Published As
| Publication number | Publication date |
|---|---|
| CN115788669B (en) | 2024-05-03 |
Similar Documents
| Publication | Publication Date | Title |
|---|---|---|
| CN102162403B (en) | System and method for estimating airflow restriction of an engine air filter | |
| US8955307B2 (en) | Exhaust gas purifying system for internal combustion engine | |
| US9874171B2 (en) | Method and device for controlling an internal combustion engine | |
| CN109441671B (en) | Diagnosis system and method for low-desorption pipeline of engine | |
| CN112983690B (en) | Flow diagnosis method and device of EGR (exhaust gas Recirculation) system and automobile | |
| CN111042941B (en) | Method for diagnosing credibility fault of air inlet temperature sensor | |
| KR101951619B1 (en) | Method for diagnosing a tank ventilation system | |
| CN113504050B (en) | Carbon deposition and coking test method and device for EGR (exhaust gas Recirculation) system | |
| CN113219938B (en) | Flow diagnosis method and system for low-pressure EGR (exhaust gas Recirculation) system of gasoline engine and readable storage medium | |
| CN113302382A (en) | Method and device for checking the functionality of a crankcase ventilation system of an internal combustion engine | |
| WO2024060689A1 (en) | Method and device for detecting air leak of engine air intake pipe | |
| CN109779742A (en) | A kind of failure monitor system and method for engine charge electronics relief valve | |
| CN109263656A (en) | Hybrid electric vehicle engine, which catches fire, coordinates diagnostic method | |
| CN111997723B (en) | Engine particle trap diagnosis method and storage medium | |
| CN110410186A (en) | The detection method and system of particle object amount, storage medium and control unit | |
| CN115788669A (en) | Crankcase ventilation system diagnosis method, device, equipment and storage medium | |
| US11920535B2 (en) | Apparatuses, methods, systems, and techniques of misfire detection using engine speed sensor | |
| CN111365147B (en) | Method for judging flow of exhaust gas recirculation system | |
| GB2558604A (en) | Method to detect faults in boost system of a turbocharged engine | |
| CN114459765B (en) | Radiator cooling efficiency monitoring method | |
| CN110109442A (en) | A kind of EMS terminal equipment failure remote diagnosis method based on various dimensions statistics | |
| CN114251199B (en) | Carbon tank desorption pipeline diagnosis method, controller and engine | |
| EP3981958B1 (en) | Systems and methods for hole detection in crankcase ventilation tubing | |
| CN110907190B (en) | Method for judging OBD remote online monitoring data quality | |
| CN115142995B (en) | Method, device, system and storage medium for monitoring exhaust gas recirculation system |
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 |