CN115788669B - 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
- CN115788669B CN115788669B CN202211343880.3A CN202211343880A CN115788669B CN 115788669 B CN115788669 B CN 115788669B CN 202211343880 A CN202211343880 A CN 202211343880A CN 115788669 B CN115788669 B CN 115788669B
- Authority
- CN
- China
- Prior art keywords
- air
- air leakage
- intake
- flowmeter
- 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.)
- Active
Links
- 238000009423 ventilation Methods 0.000 title claims abstract description 75
- 238000000034 method Methods 0.000 title claims abstract description 30
- 238000003745 diagnosis Methods 0.000 title abstract description 30
- 238000004891 communication Methods 0.000 claims description 12
- 239000003054 catalyst Substances 0.000 claims description 11
- 238000004590 computer program Methods 0.000 claims description 9
- 238000002405 diagnostic procedure Methods 0.000 claims description 9
- OKTJSMMVPCPJKN-UHFFFAOYSA-N Carbon Chemical compound [C] OKTJSMMVPCPJKN-UHFFFAOYSA-N 0.000 claims description 8
- 229910052799 carbon Inorganic materials 0.000 claims description 8
- 238000012545 processing Methods 0.000 claims description 7
- 238000001914 filtration Methods 0.000 claims description 5
- 230000010354 integration Effects 0.000 claims description 4
- 230000004069 differentiation Effects 0.000 claims description 2
- 238000012544 monitoring process Methods 0.000 abstract description 6
- 238000010586 diagram Methods 0.000 description 5
- 230000008569 process Effects 0.000 description 4
- 238000004364 calculation method Methods 0.000 description 3
- 230000000694 effects Effects 0.000 description 3
- 230000006870 function Effects 0.000 description 3
- 238000012360 testing method Methods 0.000 description 3
- 239000000356 contaminant Substances 0.000 description 2
- 230000003111 delayed effect Effects 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
- 238000010276 construction Methods 0.000 description 1
- 230000001276 controlling effect Effects 0.000 description 1
- 238000012937 correction 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
- 229920003023 plastic Polymers 0.000 description 1
- 239000004033 plastic Substances 0.000 description 1
- 231100000719 pollutant Toxicity 0.000 description 1
- 238000004064 recycling Methods 0.000 description 1
- 230000001105 regulatory effect Effects 0.000 description 1
- 230000001052 transient effect Effects 0.000 description 1
- 230000000007 visual effect Effects 0.000 description 1
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 diagnosis method, a device, equipment and a storage medium for a crankcase ventilation system, and relates to the technical field of crankcase ventilation or air exchange. In this scheme, under the condition that crankcase ventilation system high pressure end pipeline can't hardware exemption, can no longer be in order to satisfy the requirement of national Six Codes rule and newly add electrically conductive PCV pipeline, pencil, ECU PIN foot resource and the cost of special electrically conductive quick-operation joint, only accomplish the fault monitoring of discernment PCV pipeline drop phenomenon through EMS system internal logic.
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 diagnosis storage medium for a crankcase ventilation system.
Background
According to the requirements of J.4.9 in the sixth stage emission standard of China (GB 18352.6-2016), crankcase ventilation devices of automobile engines must in principle be of a closed construction, not allowing the direct emission of crankcase pollutants into the atmosphere. In order to meet regulatory requirements, crankcase contaminants are typically introduced into the intake system from the head cover via a vent tube, and re-enter the cylinder for combustion. With this configuration, the engine electronic control unit ECU must be provided with a corresponding OBD diagnostic strategy to ensure that when the crankcase ventilation line is disconnected causing crankcase contaminants to be vented directly to the atmosphere, the ECU can diagnose the disconnected fault in time and alert the driver through a visual warning system.
The current OBD diagnosis strategy has two main trends, namely, fault monitoring exemption is carried out from a hardware structure according to the J.4.9.2.3 requirement in the GB18352.6-2016 standard; secondly, a diagnosis scheme based on an electric loop is adopted to realize fault monitoring, wherein the following patent: an electrical circuit based engine crankcase ventilation (OBD) diagnostic method (CN 111765003 a) is described in detail, which requires that the PCV line must be the conductive tube of the live circuit, and that the associated line connector must also be the conductive connector, and be equipped with corresponding Engine Controller (ECU) pin resources and wiring harnesses. And this patent can adopt ordinary plastics PCV pipeline to have HFM's power assembly, through adopting the mode of the estimated air leakage diagnosis of intake manifold model discernment PCV pipeline to exist and drop, reaches the effect of reduce cost.
Disclosure of Invention
The purpose of the invention is that: the method, the device, the equipment and the storage medium are used for solving the problem that the cost is high because the related pipelines in the existing method for diagnosing the crankcase ventilation device of the engine are conductive pipelines and are provided with corresponding pin resources
In order to achieve the technical purpose, the invention adopts the following technical scheme:
In a first aspect, an embodiment of the present application provides a method for diagnosing a ventilation system of a crankcase, which is applied to a diagnosing apparatus, the diagnosing apparatus including a first flowmeter, a second flowmeter, a ventilation pipe, an intake duct, a crankcase, and an air cleaner, the crankcase including an intake manifold, the air cleaner being in communication with the intake manifold based on the intake duct, the first flowmeter being disposed on the intake duct, the second flowmeter being disposed in the intake manifold of the crankcase, one end of the ventilation pipe being connected to the intake duct, and the other end being connected to the crankcase, wherein a junction between the ventilation pipe and the intake duct is located between the first flowmeter and the intake manifold, the diagnosing method including:
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 based on 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 acquiring equivalent air leakage based on the air leakage when the air leakage reaches an initial calibration threshold;
s3: judging whether the equivalent air leakage reaches a terminal calibration threshold value or not, and selecting a corresponding fault management logic based on a judging result to complete diagnosis.
With reference to the first aspect, in some optional embodiments, the diagnostic apparatus further includes a canister solenoid valve and a brake assist vacuum pump in communication with the intake manifold, an exhaust manifold in communication with the catalyst based on a pipe, and an EGR valve further disposed on a pipe 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 further includes the following steps, before acquiring the real-time intake air amount and the theoretical model intake air amount based on the first flow meter and the second flow meter:
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 estimating the air leakage of the ventilation pipeline includes:
obtaining the difference value between the real-time air inflow and the theoretical model air inflow, and obtaining the air leakage after the difference value is subjected to low-pass filtering treatment,
With reference to the first aspect, in some optional embodiments, the obtaining an equivalent air leakage based on the air leakage is that: and correcting the air leakage based on integration to obtain the equivalent air leakage, so that the differentiation of the air leakage when the pressure of the air inlet manifold is higher can be increased based on integration of the deviation of the air leakage when the pressure of the air inlet manifold is higher under the condition that the air leakage value is smaller.
With reference to the first aspect, in some optional embodiments, when the equivalent air leakage does not reach the end calibration threshold, no fault is reported; when the equivalent air leakage reaches the end calibration threshold, judging that the ventilation pipeline is air-leaked, and reporting a fault.
In a second aspect, an embodiment of the present application further provides a diagnostic apparatus for a crankcase ventilation system, the diagnostic apparatus including a first flow meter, a second flow meter, a ventilation line, an intake duct, a crankcase, and an air cleaner, the crankcase including an intake manifold, the air cleaner being in communication with the intake manifold based on the intake duct, the first flow meter being disposed on the intake duct, the second flow meter being disposed in the intake manifold of the crankcase, one end of the ventilation line being connected to the intake duct, and the other end being connected to the crankcase, wherein a junction between the ventilation line and the intake duct is located between the first flow meter and the intake manifold, the diagnostic apparatus comprising:
an acquisition unit 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;
And the selection unit is used for judging whether the equivalent air leakage reaches the end calibration threshold value or not and selecting corresponding fault management logic based on a judgment result to finish diagnosis.
With reference to the second aspect, in some optional embodiments, the diagnostic apparatus further includes a canister solenoid valve and a brake assist vacuum pump in communication with the intake manifold, an exhaust manifold in communication with the catalyst on a pipe line basis, and an EGR valve disposed on a pipe line 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, the diagnostic device further includes:
And a switching unit controlling to close the canister solenoid valve, the brake assist vacuum pump, and the EGR valve before the first and second flow meters are collected.
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 switching 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 including a first flowmeter, a second flowmeter, a ventilation line, an intake port, a crankcase, an air cleaner, and a storage module, the crankcase including an intake manifold, the air cleaner being in communication with the intake manifold based on the intake port, the first flowmeter being disposed on the intake port, the second flowmeter being disposed in the crankcase intake manifold, one end of the ventilation line being connected to the intake port, and the other end being connected to the crankcase, wherein a junction between the ventilation line and the intake port is located between the first flowmeter and the intake manifold, and the storage module storing a computer program that, when executed by the controller, causes the diagnostic apparatus to perform the method described above.
In a fourth aspect, an embodiment of the present application further provides a computer readable storage medium, where a computer program is stored, where the computer program when executed on a computer causes the computer to perform the method described above.
The invention adopting the technical scheme has the following advantages:
The embodiment of the application provides a method, a device, equipment and a storage medium for diagnosing a crankcase ventilation system. Under the condition that a high-pressure end pipeline of a crankcase ventilation system cannot be subjected to hardware exemption, the cost of a conductive PCV pipeline, a wiring harness, an ECU PIN resource and a special conductive quick connector can be not increased for meeting the requirements of the national Six Codes rule any more, and fault monitoring for identifying the falling-off phenomenon of the PCV pipeline is achieved only through logic inside an EMS system. The application is also applicable to hybrid systems with HFM.
Drawings
The invention can be further illustrated by means of non-limiting examples given in the accompanying drawings;
FIG. 1 is a flow chart of a method of diagnosing a crankcase ventilation system according to the invention;
FIG. 2 is a schematic illustration of the connection of a diagnostic device for a crankcase ventilation system according to the invention;
FIG. 3 is a schematic diagram of a diagnostic device for a crankcase ventilation system according to the invention;
FIG. 4 is a strategy flow chart of the crankcase ventilation system diagnostic method of the invention;
The main reference numerals are as follows:
1: a first flowmeter; 2: a second flowmeter; 3: a ventilation line; 4: an air inlet channel; 5: an intake manifold; 6: an air cleaner; 7: a carbon canister solenoid valve; 8: braking an auxiliary vacuum pump; 9: an exhaust manifold; 10: a catalyst; 11: an EGR valve; 12: an acquisition unit; 13: a processing unit; 14: a controller; 15: a selection unit; 16: and a switching unit.
Detailed Description
The present invention will be described in detail below with reference to the drawings and the specific embodiments, wherein like or similar parts are designated by the same reference numerals throughout the drawings or the description, and implementations not shown or described in the drawings are in a form well known to those of ordinary skill in the art. In addition, directional terms such as "upper", "lower", "top", "bottom", "left", "right", "front", "rear", etc. in the embodiments are merely directions with reference 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, comprising a first flowmeter 1, a second flowmeter 2, a ventilation pipe 3, an intake duct 4, a crankcase and air cleaner 6, and an intake manifold 5, and further comprising a storage module. The air cleaner 6 communicates with the intake manifold 5 based on the intake passage 4. The first flowmeter 1 is provided on the intake duct 4. The second flowmeter 2 is disposed 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 is connected with the crankcase. Wherein the connection of the ventilation line 3 with the inlet duct 4 is located between the first flowmeter 1 and the inlet manifold 5. The diagnostic apparatus further comprises a canister solenoid valve 7 and a brake assist vacuum pump 8 which are in communication with the intake manifold 5, an exhaust manifold 9 and a catalyst 10, the exhaust manifold 8 is in communication with the catalyst 10 on the basis of a pipeline, an EGR valve 11 is further provided on the pipeline between the exhaust manifold 8 and the catalyst 10, the apparatus 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 flowmeter 1 is used for collecting the real-time intake air amount entering the crankcase through the air cleaner 6. The first flow meter in the present application may be an HFM (air flow meter) capable of collecting the real-time intake air amount in real time and transmitting it to the controller 14. The second flowmeter 2 is used for collecting the theoretical model intake air amount actually entered by the intake manifold 5, namely, the real-time intake air amount of a part of the air in the crankcase from the air filter 6, and the air flowing into the intake duct 4 from the direction of the ventilation pipeline 3 when the ventilation pipeline 3 leaks or falls off, wherein when the ventilation pipeline 3 leaks, the air pressure of the intake duct 4 is slightly lower than the atmospheric pressure due to the pressure drop effect of the air filter 6, and a part of the air flows into the intake duct 4 at the first joint or the second joint. It should be noted that, in the normal state, a part of the air flows into the air inlet 4 from the crankcase in the ventilation pipeline 3, but compared with the treatment process of the present application, the air flowing into the air inlet 4 from the first connector or the second connector can be totally the air leakage when the first connector or the second connector is in the falling and air leakage state. The second flowmeter 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.
The air inlet 4 is also provided with a supercharger, a throttle valve and other conventional parts, which are not repeated herein, and it is worth noting that in the conventional vehicle arrangement, the air inlet manifold 5 is also communicated with the carbon tank 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 the carbon tank electromagnetic valve 7, the brake auxiliary vacuum pump 8 and the EGR valve 11 are required to be closed before diagnosis in order to ensure the simplicity of gas sources in the air inlet manifold 5, wherein the EGR valve 11 can be closed or can be maintained at a certain opening degree (detailed later)
The controller 14 is used to record in real time the ambient temperature, the barometric pressure and engine speed, the load, the operating state of the canister solenoid valve, the EGR opening and the operating state of the vehicle brake pedal, and the controller 14 may preferably be an EMS system (engine management system).
The EGR valve 11 is used for being connected with LP-EGR (low-pressure exhaust gas in a circulation system) and delivering a part of the low-pressure exhaust gas to the intake duct 4 for recycling, and in order to ensure the uniformity of gas sources in the intake manifold 9 during diagnosis, it is also necessary to keep the EGR valve 11 closed or maintain a desired opening degree when diagnosing whether the ventilation line 3 is out of air leakage.
It should be noted that, the crankcase may also be in communication with the intake manifold 5 through the PCV low pressure section line, so as to prevent the gas in the crankcase from affecting the acquisition of the intake air amount of the theoretical model in the intake manifold 5, only the diagnosis of the falling of the ventilation line 3 (i.e., the PCV high pressure end line) at the high pressure is considered in the present application, and at this time, no gas flow or only a small amount of gas flow that does not affect the overall gas flow is allowed in the PCV low pressure end line.
The storage module stores a computer program therein which, when executed by the controller 14, enables the diagnostic device to perform the respective steps in the diagnostic method described below.
Referring to fig. 1 and 4, the embodiment of the application further provides a method for diagnosing a crankcase ventilation system. Wherein the diagnostic method may comprise the steps of:
S1: acquiring a real-time intake air amount input to the intake passage 4 by the air cleaner 6 and a theoretical model intake air amount acquired from the intake passage 4 by the intake manifold 5 based on the first flowmeter 1 and the second flowmeter 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;
s3: judging whether the equivalent air leakage reaches a terminal calibration threshold value or not, and selecting a corresponding fault management logic based on a judging result to complete diagnosis.
The steps of the crankcase ventilation system diagnostic method will be described in detail as follows:
it is to 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 air that does not pass through the first flow meter 1 enters the intake manifold 5, it is necessary to consider the following cases to be restricted to improve the reliability of diagnosis:
1) The EGR valve is opened too much or the EGR operation is unstable or the EGR valve flow deviation is too large.
2) The brake vacuum pump is operated during the diagnostic process (only the arrangement in which the vacuum source is taken from the intake manifold is considered).
3) The electromagnetic valve of the carbon tank is opened, the carbon tank is desorbed and activated, and the estimated flow of the carbon tank is inaccurate.
4) The interface of the PCV high-pressure end is smaller, so that the air leakage of the interface is not obvious after the joint 1 falls off, and the pipe diameter or the joint caliber can be properly increased.
Thus, before step S1, the following steps need to be completed:
The diagnostic enable condition determination, the controller 14 records in real time the ambient temperature, barometric pressure and engine speed, load, canister solenoid valve operating state, EGR opening, and vehicle brake pedal operating state during engine operation. The controller 14 determines whether the enabling conditions are satisfied:
Condition one: the ambient temperature is between-7 and 35 ℃ and the atmospheric pressure is higher than 70Kpa during the running process of the engine;
condition II: the EGR valve 11 opening is below the calibrated threshold: 5%;
And (3) a third condition: engine load is less than calibrated value: 25. and the engine load change rate is less than the calibration threshold: 5%;
Condition four: the engine speed is less than the calibrated value: 1500. the fluctuation of the engine speed is less than 5% of the calibration threshold value;
condition five: the brake pedal is not operated or is delayed for 5s after being operated;
condition six: the controller 14 does not monitor for the presence of any of the following faults
1. The first flowmeter 1 drives the stage and the rationality fails.
2. The second flowmeter 2 drives the stage and the rationality failure.
3. Drive stage and rationality failure of related components of a supercharging system
4. Throttle drive stage and rationality failure
5. The drive level and clamping stagnation of the electromagnetic valve 7 of the carbon tank normally open faults.
6. PCV low-voltage end drop fault (high idle)
Note that: drive stage faults include short to power faults, short to ground faults, open faults of the sensor or drive component. The rationality faults comprise Pin signal clamping stagnation, signal out-of-range and signal jump unreasonable faults of the sensor or the driving component.
After all the above six conditions are satisfied, the off-diagnosis enabling of the ventilation line 3 (PCV high pressure side line) is activated, wherein any condition is not satisfied, and the diagnosis enabling condition is judged to be reset.
In step S1, the method of estimating the intake air amount of the theoretical model of the intake manifold 5 using the second flowmeter 2 needs calibration by means of bench experiments, and calibration parameters of the conversion are given in advance by checking an ideal gas state equation (pv=nrt). For a hybrid power system engine, the bench test calibration range needs to be properly expanded. The working conditions of the first joint and the second joint when falling off are needed to be considered in the test, and the method specifically comprises the following steps:
1) Under normal conditions: 700-1500RPM, the theoretical model air inflow estimated based on the air inflow of the air inflow 5, the real-time air inflow actually measured by the first flowmeter 1, and the air inflow 5 pressure (equal gradient) estimated based on the real-time air inflow.
2) Disconnect the second joint (crankcase end) of the vent line: 700-1500RPM, the theoretical model air inflow estimated based on the pressure of the air inlet manifold 1, the real-time air inflow measured by the first flowmeter 1 and the air inlet manifold 5 pressure estimated based on the real-time air inflow.
3) Disconnect the first connection (air filter end) of the ventilation line: 700-1500RPM, the theoretical model air inflow estimated based on the pressure of the air inlet manifold 1, the real-time air inflow measured by the first flowmeter 1 and the air inlet manifold 5 pressure estimated based on the real-time air inflow.
The effective difference between the inlet air flow estimated based on the manifold pressure in the step 1) and the step 2) and the step 3) is confirmed through the bench data, and is used for adjusting reference and threshold division of the follow-up air leakage integral coefficient, and synchronously confirming the most reliable rotating speed-load diagnosis area.
Confirming the estimated theoretical model air inflow through table lookup:
Horizontal axis: based on the pressure array of the intake manifold 1
For example, intake manifold pressure [30,40,50,60,70,80,110], units Kpa;
Checking the mark value: estimating the air inflow of the theoretical model based on the pressure of the air inlet manifold;
for example, the intake air flow rate [1.9,2.5,3,4,6,8, 15] is estimated in g/s.
Based on the temperature of the intake manifold 5, appropriate corrections to the estimated intake air flow are required, and the coefficient is calibratable.
After the diagnostic enable is activated, the controller 14 requests to stop the canister solenoid valve 7 from desorbing, and after the canister solenoid valve 7 is closed, the internal diagnostic routine activates the relevant data sampling. The method specifically comprises the following sampling data:
And (3) a step of: the real-time intake air amount (A1) measured by the first flowmeter 1;
and II: the theoretical model intake air amount (A2) calculated based on the second flowmeter 2.
In step S2, the air leakage of the ventilation pipeline 3 is estimated based on the real-time air inflow and the theoretical model air inflow, and an equivalent air leakage is obtained based on the air leakage when the air leakage reaches an initial calibration threshold. That is, the difference between (A1) and (A2) is estimated to estimate the air leakage amount (A3) at the falling-off position of the ventilation pipe 3. In theory, the difference 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 fallen out of the ventilation pipeline 3. It should be noted that, the following calculation should be performed after the low-pass filtering of the A3 to eliminate the erroneous judgment phenomenon caused by the transient large pressure deviation, 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 period, and K1 reflects the filtering speed.
In general, in the absence of PCV line sloughing, A3 fluctuates in a small range around 0; when the ventilation line 3 is detached, the air pressure in the air inlet 4 behind the first flowmeter 1 is slightly lower than the atmospheric pressure due to the pressure drop effect of the air filter 6, so that part of air flows into the air inlet at the first connector or the second connector, and the air flow finally entering the air inlet manifold 5 deviates from the air inlet flow measured by the first flowmeter 1, namely, the A3 deviates from the vicinity of 0.
Through actual bench measurement, the air leakage A3 is directly proportional to the joint aperture of the ventilation pipeline 3 and inversely proportional to the pressure of the ventilation pipeline 3. In general, the air leakage after the release of the ventilation line 3 is most remarkable under idle conditions.
When the controller 14 detects that the value of the absolute value A3 is smaller than the initial calibration threshold (2 g/s), the theoretical model air inflow is equivalent to the actually measured air inflow, no air leakage phenomenon exists, and the diagnosis is performed to quickly pass after the calibration time is delayed for 3s (FastPass).
When |A3| is greater than the initial calibration threshold (2 g/s), a virtual equivalent air leakage (A4) is calculated by the following calculation formula:
The time t can be calibrated according to the continuous time of the average steady-state area of the power assembly in the WLTC, the integral coefficient K2 can adjust the integral speed, and the calibration is comprehensively calibrated according to the requirement of the time for fault reporting. The adoption of an integral mode to correct the equivalent air leakage can enhance the applicability of the logic. When the pressure of the intake manifold 5 is higher and the like in the steady state, and the overall A3 is lower, the air leakage phenomenon can be amplified by integrating the deviation of the air quantity, and the distinction degree from the normal state can be increased.
In step S3, it is determined whether the equivalent air leakage reaches the end calibration threshold, and a corresponding fault management logic is selected based on the determination result, so as to complete diagnosis. When FastPass logic is met, diagnosis can be quickly passed, diagnosis is completed, 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).
When A4 reaches or exceeds the end calibration threshold, the controller 14 judges that the ventilation pipeline 3 falls off and faults exist, diagnosis is completed, and the faults are reported. And (3) storing fault codes, lighting an MIL lamp and storing a frozen frame according to the requirements of regulations, and ending diagnosis after IUPR molecules are grown. It is suggested that the present diagnostic strategy allows for multiple attempts in the same driving cycle, the number of attempts being scalable. Once the diagnosis is completed, no further attempts are made for the current driving cycle.
The final calibration threshold value needs to consider the condition that the first joint and the second joint are respectively fallen off, and needs to consider a mode that the air leakage is least obvious as a basis for the calibration test division threshold value.
With continued reference to fig. 2 and3, the present application also provides a crankcase ventilation System diagnostic device that includes at least one software functional module that may be stored in a memory module in the form of software or Firmware (Firmware) or cured in an Operating System (OS) of a diagnostic device. The controller 14 is used to execute executable modules stored in a memory module, such as software functional modules and computer programs included in the diagnostic device.
The diagnostic device comprises an acquisition unit 12, a processing unit 13 and a selection unit 15, each of which has the following functions:
An acquisition unit 12 that acquires a real-time intake air amount input to the intake passage 4 by the air cleaner 6 and a theoretical model intake air amount acquired from the intake passage 4 by the intake manifold 5 based on the first flowmeter 1 and the second flowmeter 2;
A processing unit 13, which estimates the air leakage of the ventilation pipeline 3 based on the real-time air inflow and the theoretical model air inflow and obtains equivalent air leakage based on the air leakage when the air leakage reaches an initial calibration threshold;
And the selection unit 15 judges whether the equivalent air leakage reaches a terminal calibration threshold value or not, and selects corresponding fault management logic based on a judgment result to complete 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 and second flow meters 1 and 2 collect the respective air flow rates. The switching unit 16 can close the gas line that may have an influence or error on the calculation of the intake air amount of the theoretical model in the intake manifold 5 before the diagnosis starts, ensuring the accuracy of the gas source in the intake manifold 5.
In this embodiment, the memory 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, etc. In this embodiment, the storage module may be configured to store the collected data of the first flowmeter 1 and the second flowmeter 2, the initial calibration threshold, the terminal calibration threshold, 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 only 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 brevity of description, specific working processes of the diagnostic apparatus and the diagnostic device described above may refer to corresponding processes of each step in the foregoing method, and will not be described in detail herein.
The embodiment of the application also provides a computer readable storage medium. A computer readable storage medium has stored therein a computer program which, when run on a computer, causes the computer to perform the ventilation system diagnostic method as described in the above embodiments.
From the foregoing description of the embodiments, it will be apparent to those skilled in the art that the present application may be implemented in hardware, or by means of software plus a necessary general hardware platform, and based on this understanding, the technical solution of the present application may be embodied in the form of a software product, which may be stored in a non-volatile storage medium (may be a CD-ROM, a U-disc, a removable hard disk, etc.), and includes several instructions for causing a computer device (may be a personal computer, a diagnostic device, or a network device, etc.) to execute the method described in the respective implementation scenario of the present application.
In summary, embodiments of the present application provide a method, apparatus, device and 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 subjected to hardware exemption, the cost of a conductive PCV pipeline, a wiring harness, an ECU PIN resource and a special conductive quick connector can be not increased for meeting the requirements of the national Six Codes rule any more, and fault monitoring for identifying the falling-off phenomenon of the PCV pipeline is achieved only through logic inside an EMS system. The application 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 manners as well. The above-described apparatus, system, and method embodiments are merely illustrative, for example, flow charts 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 a single part, or each module may exist alone, or two or more modules may be integrated to form a single 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 variations will be apparent to those skilled in the art. Any modification, equivalent replacement, improvement, etc. made within the spirit and principle of the present application should be included in the protection scope of the present application.
Claims (8)
1. A method for diagnosing a crankcase ventilation system, characterized by being applied to a diagnosing apparatus comprising a first flowmeter (1), a second flowmeter (2), a ventilation line (3), an intake duct (4), a crankcase and an air cleaner (6), and an intake manifold (5), the air cleaner (6) being communicated with the intake manifold (5) based on the intake duct (4), the first flowmeter (1) being provided on the intake duct (4), the second flowmeter (2) being provided in the intake manifold (5), one end of the ventilation line (3) being connected with the intake duct (4), the other end being connected with the crankcase, wherein a junction of the ventilation line (3) and the intake duct (4) is located between the first flowmeter (1) and the intake manifold (5), the diagnosing method comprising the steps of: s1: acquiring a real-time intake air amount input into the intake passage (4) by the air cleaner (6) and a theoretical model intake air amount acquired from the intake passage (4) by the intake manifold (5) based on the first flowmeter (1) and the second flowmeter (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; s3: judging whether the equivalent air leakage reaches a terminal calibration threshold value or not, selecting a corresponding fault management logic based on a judgment result, and predicting the air leakage of the ventilation pipeline (3) to be as follows: obtaining the difference value between the real-time air inflow and the theoretical model air inflow, and obtaining the air leakage after the difference value is subjected to low-pass filtering treatment, wherein the equivalent air leakage is obtained based on the air leakage and is as follows: and correcting the air leakage based on integration to obtain the equivalent air leakage, so that the differentiation of the air leakage when the pressure of the air inlet manifold (5) is higher can be increased based on integration of the air leakage deviation under the condition that the air leakage value is smaller due to the higher pressure of the air inlet manifold (5).
2. The crankcase ventilation system diagnostic method according to claim 1, characterized in that the diagnostic device further comprises a canister solenoid valve (7) and a brake assist vacuum pump (8) in communication with the intake manifold (5), an exhaust manifold (9) and a catalyst (10), the exhaust manifold (9) being in communication with the catalyst (10) on a pipe basis, an EGR valve (11) being further provided on a pipe between the exhaust manifold (9) and the catalyst (10), the device further comprising a controller (14), the controller (14) being electrically connected to the first and second flow meters (1, 2), respectively, and further comprising the steps of, before obtaining the real-time intake air amount and the theoretical model intake air amount on the basis of the first and second flow meters (1, 2): -closing the canister solenoid valve (7), the brake assist vacuum pump (8) and the EGR valve (11).
3. The crankcase ventilation diagnostic method of claim 2, wherein no fault is reported when the equivalent air leakage does not reach the tip calibration threshold; when the equivalent air leakage reaches the end calibration threshold, judging 2 that the ventilation pipeline (3) is in air leakage, and reporting a fault.
4. A crankcase ventilation system diagnostic device for use with the diagnostic apparatus of claim 2, the diagnostic device comprising: an acquisition unit (12) for acquiring a real-time intake air amount input into the intake passage (4) by the air cleaner (6) and a theoretical model intake air amount acquired from the intake passage (4) by the 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 acquires equivalent air leakage based on the air leakage when the air leakage reaches an initial calibration threshold; and the selection unit (15) is used for judging whether the equivalent air leakage reaches the end calibration threshold value or not and selecting corresponding fault management logic based on a judgment result.
5. The crankcase ventilation system diagnostic device of claim 4, further comprising: and a switch unit (16) for controlling the closing of the carbon tank electromagnetic valve (7), the brake auxiliary vacuum pump (8) and the EGR valve (11) before the first flowmeter (1) and the second flowmeter (2) collect.
6. The crankcase ventilation system diagnostic device according to claim 5, wherein the acquisition unit (12), the processing unit (13) and the selection unit (15) are each coupled to the controller (14), the switching unit (16) being coupled to the controller (14).
7. A diagnostic device as claimed in claim 6, characterized in that it further comprises a storage module in which a computer program is stored which, when executed by the controller (14), causes the diagnostic device to perform the method as claimed in any of claims 1-3.
8. A computer readable storage medium, characterized in that the computer readable storage medium has stored therein a computer program which, when run on a computer, causes the computer to perform the method according to any of claims 1-3.
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 CN115788669A (en) | 2023-03-14 |
| CN115788669B true 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 (10)
| 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 |
| KR20120074034A (en) * | 2010-12-27 | 2012-07-05 | 주식회사 포스코 | Method for correcting injection amount of a pulverized coal into blow furnace |
| 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 |
Family Cites Families (3)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| DE10320054A1 (en) * | 2003-05-06 | 2004-11-25 | Robert Bosch Gmbh | Method and device for operating an internal combustion engine |
| US9957906B2 (en) * | 2013-11-06 | 2018-05-01 | Ford Gloabl Technologies, LLC | Methods and systems for PCV flow estimation with an intake oxygen sensor |
| CN106321301B (en) * | 2015-06-30 | 2021-02-02 | 福特环球技术公司 | Positive crankcase ventilation device and related engine assembly |
-
2022
- 2022-10-31 CN CN202211343880.3A patent/CN115788669B/en active Active
Patent Citations (10)
| 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 |
| KR20120074034A (en) * | 2010-12-27 | 2012-07-05 | 주식회사 포스코 | Method for correcting injection amount of a pulverized coal into blow furnace |
| 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 |
|---|
| 发动机进气歧管稳压腔结构优化;李军;饶均;田延庆;张世艺;;计算机仿真;20160815(08);第158-162页 * |
Also Published As
| Publication number | Publication date |
|---|---|
| CN115788669A (en) | 2023-03-14 |
Similar Documents
| Publication | Publication Date | Title |
|---|---|---|
| US6257214B1 (en) | Exhaust gas recirculation monitor | |
| CN102162403B (en) | System and method for estimating airflow restriction of an engine air filter | |
| US9874171B2 (en) | Method and device for controlling an internal combustion engine | |
| EP3179087B1 (en) | Error determination unit | |
| US20110197864A1 (en) | Internal combustion engine and method for monitoring a tank ventilation system and a crankcase ventilation system | |
| CN109441671B (en) | Diagnosis system and method for low-desorption pipeline of engine | |
| US20130304359A1 (en) | Diagnosis method | |
| CN104074603A (en) | Method for purging charge air cooler condensate during compressor bypass valve event | |
| US9470186B2 (en) | Method for diagnosing a tank ventilation system | |
| US20090266151A1 (en) | Method and Device for Adapting the Efficiency of a Cooler in the Return Circuit of Exhaust Gas in an Internal Combustion Engine | |
| CN108590868B (en) | Diagnosis method and system for natural gas engine supercharger control system | |
| US10794244B2 (en) | Method and system for crankcase ventilation monitor | |
| CN110671220A (en) | Method and system for diagnosing leaks in a fuel vapor double purge system | |
| EP2058493A1 (en) | A diagnostic method for a vehicle engine apparatus, provided with sensors | |
| US20080051943A1 (en) | Apparatus for calculating detection error of fresh air quantity detection device | |
| CN113302382A (en) | Method and device for checking the functionality of a crankcase ventilation system of an internal combustion engine | |
| CN111779587A (en) | Fault diagnosis method and system for double purification system | |
| CN115788669B (en) | Crankcase ventilation system diagnosis method, device, equipment and storage medium | |
| CN117212002A (en) | Leakage detection method of fuel evaporation system and electronic equipment | |
| US11326540B2 (en) | Abnormality determination device of internal combustion engine | |
| GB2558604A (en) | Method to detect faults in boost system of a turbocharged engine | |
| CN107476892B (en) | Engine control method and system and vehicle | |
| EP1541841A1 (en) | Method for diagnosis of the faults in units of an internal combustion engine air supply system | |
| KR20220026736A (en) | System and method for diagnosis of vehicle purge line | |
| CN114459765B (en) | Radiator cooling efficiency monitoring method |
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 |