CN115075970A - System for internal combustion engine, method of operating the same, and medium storing corresponding program - Google Patents
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- 238000002485 combustion reaction Methods 0.000 title claims abstract description 47
- 238000000034 method Methods 0.000 title claims abstract description 32
- 239000000446 fuel Substances 0.000 claims abstract description 215
- 238000012937 correction Methods 0.000 claims abstract description 98
- 238000010926 purge Methods 0.000 claims abstract description 31
- OKTJSMMVPCPJKN-UHFFFAOYSA-N Carbon Chemical compound [C] OKTJSMMVPCPJKN-UHFFFAOYSA-N 0.000 claims abstract description 28
- 229910052799 carbon Inorganic materials 0.000 claims abstract description 27
- 230000004044 response Effects 0.000 claims abstract description 16
- 238000011017 operating method Methods 0.000 claims abstract description 12
- 238000000746 purification Methods 0.000 claims abstract description 12
- 239000002828 fuel tank Substances 0.000 claims description 19
- 238000012544 monitoring process Methods 0.000 claims description 5
- 238000012935 Averaging Methods 0.000 claims description 3
- 238000004590 computer program Methods 0.000 claims description 2
- 230000001419 dependent effect Effects 0.000 claims description 2
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- 230000032683 aging Effects 0.000 description 2
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- 229930195733 hydrocarbon Natural products 0.000 description 2
- 150000002430 hydrocarbons Chemical class 0.000 description 2
- 238000012804 iterative process Methods 0.000 description 2
- CBENFWSGALASAD-UHFFFAOYSA-N Ozone Chemical compound [O-][O+]=O CBENFWSGALASAD-UHFFFAOYSA-N 0.000 description 1
- 239000000809 air pollutant Substances 0.000 description 1
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- F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
- F02—COMBUSTION ENGINES; HOT-GAS OR COMBUSTION-PRODUCT ENGINE PLANTS
- F02D—CONTROLLING COMBUSTION ENGINES
- F02D41/00—Electrical control of supply of combustible mixture or its constituents
- F02D41/02—Circuit arrangements for generating control signals
- F02D41/14—Introducing closed-loop corrections
- F02D41/1401—Introducing closed-loop corrections characterised by the control or regulation method
-
- F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
- F02—COMBUSTION ENGINES; HOT-GAS OR COMBUSTION-PRODUCT ENGINE PLANTS
- F02D—CONTROLLING COMBUSTION ENGINES
- F02D41/00—Electrical control of supply of combustible mixture or its constituents
- F02D41/0025—Controlling engines characterised by use of non-liquid fuels, pluralities of fuels, or non-fuel substances added to the combustible mixtures
- F02D41/003—Adding fuel vapours, e.g. drawn from engine fuel reservoir
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- F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
- F02—COMBUSTION ENGINES; HOT-GAS OR COMBUSTION-PRODUCT ENGINE PLANTS
- F02D—CONTROLLING COMBUSTION ENGINES
- F02D41/00—Electrical control of supply of combustible mixture or its constituents
- F02D41/02—Circuit arrangements for generating control signals
- F02D41/14—Introducing closed-loop corrections
- F02D41/1401—Introducing closed-loop corrections characterised by the control or regulation method
- F02D41/1406—Introducing closed-loop corrections characterised by the control or regulation method with use of a optimisation method, e.g. iteration
-
- F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
- F02—COMBUSTION ENGINES; HOT-GAS OR COMBUSTION-PRODUCT ENGINE PLANTS
- F02M—SUPPLYING COMBUSTION ENGINES IN GENERAL WITH COMBUSTIBLE MIXTURES OR CONSTITUENTS THEREOF
- F02M25/00—Engine-pertinent apparatus for adding non-fuel substances or small quantities of secondary fuel to combustion-air, main fuel or fuel-air mixture
- F02M25/08—Engine-pertinent apparatus for adding non-fuel substances or small quantities of secondary fuel to combustion-air, main fuel or fuel-air mixture adding fuel vapours drawn from engine fuel reservoir
- F02M25/0836—Arrangement of valves controlling the admission of fuel vapour to an engine, e.g. valve being disposed between fuel tank or absorption canister and intake manifold
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- F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
- F02—COMBUSTION ENGINES; HOT-GAS OR COMBUSTION-PRODUCT ENGINE PLANTS
- F02M—SUPPLYING COMBUSTION ENGINES IN GENERAL WITH COMBUSTIBLE MIXTURES OR CONSTITUENTS THEREOF
- F02M25/00—Engine-pertinent apparatus for adding non-fuel substances or small quantities of secondary fuel to combustion-air, main fuel or fuel-air mixture
- F02M25/08—Engine-pertinent apparatus for adding non-fuel substances or small quantities of secondary fuel to combustion-air, main fuel or fuel-air mixture adding fuel vapours drawn from engine fuel reservoir
- F02M25/0854—Details of the absorption canister
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- Y—GENERAL TAGGING OF NEW TECHNOLOGICAL DEVELOPMENTS; GENERAL TAGGING OF CROSS-SECTIONAL TECHNOLOGIES SPANNING OVER SEVERAL SECTIONS OF THE IPC; TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS
- Y02—TECHNOLOGIES OR APPLICATIONS FOR MITIGATION OR ADAPTATION AGAINST CLIMATE CHANGE
- 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
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- Engineering & Computer Science (AREA)
- Chemical & Material Sciences (AREA)
- Combustion & Propulsion (AREA)
- Mechanical Engineering (AREA)
- General Engineering & Computer Science (AREA)
- Combined Controls Of Internal Combustion Engines (AREA)
Abstract
The invention relates to a system for an internal combustion engine, a method of operating the same and a medium storing a corresponding program. When the internal combustion engine system is in the learning mode, the operating method includes: acquiring a fuel learning value; when the fuel learning value is smaller than the fuel limit value, exiting the learning mode, closing the carbon tank purification valve and opening the carbon tank pressure release valve; acquiring a pressure value in the carbon tank and an actual air-fuel ratio correction value to calculate an ideal air-fuel ratio correction value; judging whether there is a mis-learning based on the ideal air-fuel ratio correction value ALPHA and the actual air-fuel ratio correction value n; restoring the fuel learned value to a previous value in response to determining that there is a mis-learning; re-entering the learning mode after a time period T in response to determining that there is no mis-learning; and closing the canister relief valve and opening the canister purge valve.
Description
Technical Field
The present invention relates to the field of vehicle control, and in particular to an operating method for an internal combustion engine system, a system for an internal combustion engine and a medium having a corresponding program stored thereon.
Background
An engine control system of a vehicle utilizes a fuel monitoring device to check and adjust long-term fuel correction values, also referred to as fuel learned values. Specifically, the engine control system feeds back the air-fuel ratio according to the sensor signal, and corrects and adjusts the fuel injection pulse width so that the air-fuel ratio is infinitely close to an ideal value. However, the control range of the feedback correction is limited, and when the center of the feedback value is biased to the rich or lean side for a long time, the learning correction coefficient (λ) is set according to the change of the feedback value, so as to realize the long-term correction of the fuel injection. The learning correction coefficient (λ) is stored in a nonvolatile memory of an Electronic Control Unit (ECU). The value of the learning correction coefficient (lambda) is not deleted even if the ignition switch is turned off, so that the ECU performs the fuel injection correction using the learning correction coefficient (lambda) calculated last when the ignition switch is turned on next time.
The boil-off gas in the fuel tank is composed of Hydrocarbons (HC), and when discharged into the atmosphere, it becomes an air pollutant that induces ozone layer destruction and the like. Therefore, in the vehicle, the evaporated gas generated due to the evaporation of the fuel is captured in the canister. The carbon tank is connected with the fuel tank and the air inlet pipe, and the adsorption capacity of the activated carbon is utilized to absorb steam generated by fuel volatilization of the fuel tank. When the pressure in the carbon tank reaches a certain value, a purification valve of the carbon tank is opened to introduce fuel into the air inlet pipe to participate in combustion. In the national six standards, the carbon tank is provided with a pressure sensor for detecting the pressure in the carbon tank, and when the pressure value exceeds the limit, a pressure release valve must be opened to release the fuel steam in the carbon tank.
The gasoline evaporated from the canister may affect the learning value, resulting in mis-learning. The deviation of the air quantity after the error learning can cause bad phenomena such as emission deterioration and performance reduction. Deviation of the learned value may also cause deviation of the air-fuel ratio from the stoichiometric air-fuel ratio (e.g., 14.7), leading to deterioration of emissions, power attenuation, and the like. The long-term presence of mis-learning may also accelerate aging or clogging of components.
Therefore, there is a need in the art for a technique that avoids the occurrence of mis-learning while simultaneously compromising the opening of the canister purge capability to avoid the problems of gasoline vapor odor, etc.
Disclosure of Invention
The present invention is directed to overcoming the above-mentioned and/or other problems of the prior art, and in particular, to efficiently determining whether a mis-learning is caused in a fuel learning mode and adopting a corresponding control strategy while more precisely controlling the timing of canister purge opening and closing.
Accordingly, an exemplary embodiment of the present invention provides an operating method for an internal combustion engine system, the internal combustion engine system being in a learning mode, the operating method comprising: acquiring a fuel learning value; when the fuel learning value is smaller than the fuel limit value, the learning mode is exited, the carbon tank purification valve is closed, and the carbon tank pressure release valve is opened; acquiring a pressure value in the carbon tank and an actual air-fuel ratio correction value to calculate an ideal air-fuel ratio correction value; judging whether there is a mis-learning based on the stoichiometric air-fuel ratio correction value ALPHA and the actual air-fuel ratio correction value n; restoring the fuel learned value to a previous value in response to determining that there is mis-learning; re-entering the learning mode after a time period T in response to determining that there is no mis-learning; and closing the canister relief valve and opening the canister purge valve.
According to another exemplary embodiment, there is provided a system for an internal combustion engine, the system comprising: a canister that captures fuel vapor generated from the fuel tank; a canister purge valve that supplies fuel vapor in the canister to an intake pipe of an internal combustion engine when opened; a canister relief valve that releases fuel vapor within the canister to atmosphere when opened; and a control unit including: a memory for storing data relating to the canister and the internal combustion engine, wherein the data includes a fuel learning value, a pressure value within the canister, and an actual air-fuel ratio correction value; and a processor for performing the following operations when the system is in a learn mode and the canister purge valve is open: acquiring a fuel learning value; when the fuel learning value is smaller than a fuel limit value, exiting the learning mode, closing the carbon tank purification valve and opening the carbon tank pressure release valve; acquiring a pressure value in the carbon tank and an actual air-fuel ratio correction value to calculate an ideal air-fuel ratio correction value; determining whether there is a mis-learning based on the stoichiometric air-fuel ratio correction value and the actual air-fuel ratio correction value; restoring the fuel learned value to a previous value in response to determining that there is mis-learning; re-entering the learning mode after a period of time in response to determining that there is no mis-learning; and closing the canister relief valve and opening the canister purge valve.
Preferably, the fuel limit is determined by: initially setting the fuel limit value as a system-set lower limit value of a fuel learning value; continuously monitoring a fuel learning value and a fuel learning value gain; and when the gain for N consecutive fuel learned values is negative, determining the fuel limit value using the following equation: the fuel limit is the current fuel learned value gain (current fuel learned value-previous fuel learned value) + the system set lower limit.
Preferably, the stoichiometric air-fuel ratio correction value ALPHA is calculated by the following equation: ALPHA ═ nxe C×P Where n is an actual air-fuel ratio correction value in the canister purge valve closed state, P is the canister internal pressure value, and C is a constant depending on the remaining fuel percentage of the fuel tank.
Preferably, the processor further calculates the air-fuel ratio correction deviation value σ ═ α × X-n, where X is a tank volume correction coefficient set according to the volume of the fuel tank. Preferably, the time period T ═ txe 0.3σ Wherein t is a default learning standard time of the internal combustion engine system.
Preferably, the operation of determining whether there is a mis-learning includes: obtaining N ideal air-fuel ratio correction values ALPHA and averaging the correction values ALPHA to obtain an average value ALAVE; calculating a discrete coefficient between the actual air-fuel ratio correction value n and the average value ALAVE; determining whether the discrete coefficient is within a threshold interval; and in response to determining that the discrete coefficients are within a threshold interval, determining that there is no mis-learning; or determining that there is mis-learning in response to determining that the discrete coefficients are outside of a threshold interval.
Preferably, in the case where the system is in the learning mode, if the vehicle speed of the vehicle in which the system is located increases from 0 while the stoichiometric air-fuel ratio correction value ALPHA abruptly changes, the learning mode is exited, and the learning mode is reentered after the time period T.
According to a further exemplary embodiment, a computer-readable storage medium is provided, on which a computer program is stored which, when being executed by a processor, carries out the method of operation as set forth above.
Other features and aspects will become apparent from the following detailed description, the accompanying drawings, and the claims.
Drawings
The invention may be better understood by describing exemplary embodiments thereof in conjunction with the following drawings, in which:
FIG. 1 shows a schematic block diagram of a system according to an exemplary embodiment of the invention;
FIG. 2 is a flow chart of a method of operation for an internal combustion engine system according to an exemplary embodiment of the present invention;
FIG. 3 shows a schematic graph of the pressure value (P) in the canister versus the stoichiometric correction value (ALPHA) for different percentages of remaining fuel;
FIG. 4 illustrates an example process of determining whether there is a mis-learning;
FIG. 5 is a diagram showing a schematic of calculating the four-point average value ALAVE of the stoichiometric air-fuel ratio correction value ALPHA;
FIG. 6 shows a graph relating correction factor X to the volume of the fuel tank;
fig. 7 is a graph showing the relationship between the deviation value (σ) and the learning prohibition time (T);
FIG. 8 shows a timing diagram of a first example process utilizing an internal combustion engine system and method of operating the same according to an example embodiment;
FIG. 9 shows a timing diagram of a second example process utilizing an internal combustion engine system and method of operating the same according to an example embodiment; and
fig. 10 shows a time chart of a third example process using the internal combustion engine system and the operation method thereof according to the example embodiment.
Detailed Description
While specific embodiments of the invention will be described below, it should be noted that in the course of the detailed description of these embodiments, in order to provide a concise and concise description, all features of an actual implementation may not be described in detail. It should be appreciated that in the development of any such actual implementation, as in any engineering or design project, numerous implementation-specific decisions are made to achieve the developers' specific goals, such as compliance with system-related and business-related constraints, which may vary from one implementation to another. Moreover, it should be appreciated that in the development of any such actual implementation, as in any engineering or design project, numerous implementation-specific decisions must be made to achieve the developers' specific goals, such as compliance with system-related and business-related constraints, which may vary from one implementation to another.
Unless otherwise defined, technical or scientific terms used in the claims and the specification should have the ordinary meaning as understood by those of ordinary skill in the art to which the invention belongs. The use of "first," "second," and similar terms in the description and claims of the present application do not denote any order, quantity, or importance, but rather the terms are used to distinguish one element from another. The terms "a" or "an," and the like, do not denote a limitation of quantity, but rather denote the presence of at least one. The word "comprise" or "comprises", and the like, means that the element or item listed before "comprises" or "comprising" covers the element or item listed after "comprising" or "comprises" and its equivalent, and does not exclude other elements or items. The terms "connected" or "coupled" and the like are not restricted to physical or mechanical connections, nor are they restricted to direct or indirect connections.
A system for an internal combustion engine and an operating method thereof according to an embodiment of the present invention will be described in detail with reference to the accompanying drawings.
Referring to fig. 1, fig. 1 shows a schematic block diagram of a system according to an exemplary embodiment of the present invention. As shown in fig. 1, a system 100 for an internal combustion engine according to an exemplary embodiment of the present invention may include a canister 110, a canister purge valve 120, a canister relief valve 130, and a control unit 140.
The canister 110 is disposed between the fuel tank and the internal combustion engine and may capture fuel vapor generated from the fuel tank. Canister purge valve 120, when open, may supply fuel vapor within canister 110 to the intake of the internal combustion engine. Canister relief valve 130, when open, may release fuel vapor within canister 110 to the atmosphere.
The control unit 140 may control the opening and closing degrees of the canister purge valve 120 and the canister relief valve 130. The control unit 140 may include a memory 141 and a processor 142. Memory 414 may store data related to canister 110 and the internal combustion engine. These data may include sensed data measured via sensors, feedback data calculated based on the sensed data, and preset parameters associated with canister 110, the internal combustion engine, and the vehicle in which the internal combustion engine is located. In an exemplary embodiment of the present invention, the data may include a fuel learning value, a pressure value in the canister, and an actual air-fuel ratio correction value.
The system 100 (and more particularly the control unit 140) may enter a learn mode to check and adjust the long term fuel correction value, i.e., the above-described fuel learn value, using a fuel monitoring device (not shown). Specifically, the control unit 140 may perform feedback of the air-fuel ratio based on the sensor signal, and adjust the fuel injection pulse width in a correction manner so that the air-fuel ratio approaches an ideal value infinitely. The fuel learned value may be stored in the memory 141 of the control unit 140. The fuel learning value is not deleted even if the ignition switch is turned off, so that the control unit 140 performs the fuel injection correction using the last calculated fuel learning value when the ignition switch is turned on next time.
When the system 100 is in the canister purge mode (i.e., when the canister purge valve 120 is open), the accuracy of the learned value may be affected due to fuel vapor in the canister 110 being introduced into the intake pipe to participate in combustion, resulting in mis-learning.
Therefore, the invention provides a method for judging whether the purification mode causes the mis-learning and a corresponding processing strategy. Referring to FIG. 2, FIG. 2 is a flow chart of a method 200 of operation for an internal combustion engine system according to an exemplary embodiment of the present invention. The method of operation 200 may be implemented by the control unit 140, in particular the processor 142. The operation method 200 may include the following steps S210 to S260.
In step S210, a fuel learning value is acquired. The fuel learned value may be determined by a fuel monitoring device (not shown) of the internal combustion engine system and stored in the processor so that the fuel learned value may be retrieved from the memory in real time.
In step S220, when the fuel learned value is less than the fuel limit, the learning mode is exited, the canister purge valve is closed, and the canister relief valve is opened.
In some embodiments of the invention, the fuel limit may be determined by: initially setting the fuel limit value as a system setting lower limit value of a fuel learning value; continuously monitoring a fuel learning value and a fuel learning value gain; and when the gain for N consecutive fuel learned values is negative, determining the fuel limit value using the following equation: the fuel limit is the current fuel learned value gain (current fuel learned value-previous fuel learned value) + the system set lower limit. The system setting lower limit value is a preset parameter relating to the internal combustion engine, and is stored in the nonvolatile memory of the control unit. The above determination of the fuel limit is based on the following considerations: on the basis of the lower limit value set by the system, the compensation correction of the limit value is carried out according to the gain of the actual data through the calculation, so that the integral deviation of the learning value caused by factors such as the running condition, the individual difference of components of the fuel system and the air metering system, the aging of the components and the like can be corrected in real time.
In this way, if the current fuel learning value is smaller than the set fuel limit value, it is assumed that the fuel learning value continues to decrease in the canister purge mode, and there is a possibility that the fuel learning value deviates due to a mis-learning. At this time, it is necessary to exit the learning mode and turn off the canister purge mode to make the rationality determination of the fuel learned value. Because the canister purge valve is closed, fuel vapor in the fuel tank can continuously enter the canister, and therefore in order to ensure that the pressure in the canister does not increase too quickly, the canister relief valve needs to be opened to relieve the increase in pressure in the canister.
In step S230, the in-canister pressure value and the actual air-fuel ratio correction value are acquired to calculate the stoichiometric air-fuel ratio correction value.
The in-canister pressure value and the actual air-fuel ratio correction value may be read from the memory of the control unit, and these values are monitored in real time (e.g., every 10 milliseconds) via the fuel monitoring device and recorded in the memory.
In some embodiments of the invention, the stoichiometric air-fuel ratio correction value (ALPHA) may be calculated by the following equation: ALPHA-nxe C×P Where n is the actual air-fuel ratio correction value with the canister purge valve closed, P is the canister pressure value, and C is a constant dependent on the percentage of fuel remaining in the fuel tank. Note that n, P and C may all be read from the memory of the control unit of the internal combustion engine system, or C may also be defined experimentally depending on the actual operating conditions. Referring to fig. 3, a schematic graph of the in-canister pressure value (P) versus the stoichiometric correction value (ALPHA) for different percentages of remaining fuel is shown, where each curve corresponds to a different constant C for different percentages of remaining fuel.
In step S240, it is determined whether there is a mis-learning based on the stoichiometric air-fuel ratio correction value (ALPHA) and the actual air-fuel ratio correction value (n).
In some embodiments of the present invention, the step of determining whether there is a mis-learning may include the following sub-steps S410-S450.
Referring to FIG. 4, in sub-step S410, N stoichiometric correction values ALPHA may be obtained and averaged to obtain an average value ALAVE. For example, assuming that the system monitors and records the in-canister pressure value and the actual air-fuel ratio correction value every 10 milliseconds, 4 in-canister pressure values and 4 corresponding actual air-fuel ratio correction values for 40 milliseconds may be obtained to calculate 4 stoichiometric air-fuel ratio correction values, and then four-point average value ALAVE may be calculated for the 4 stoichiometric air-fuel ratio correction values, as shown in FIG. 5.
In sub-step S420, a dispersion coefficient between actual air-fuel ratio correction value n and average value ALAVE is calculated. As an example, the discrete coefficient (V) may be represented by an equation
And calculating according to a standard deviation formula, wherein s is the standard deviation between the actual air-fuel ratio correction value n and the average value ALAVE.
In sub-step S430, it is determined whether the discrete coefficient (V) is within a threshold interval.
The threshold interval can be set differently according to different internal combustion engine types and different conditions such as vehicle running conditions, mileage, external environment temperature and atmospheric pressure. As an example, the threshold interval may be set to [ 0%, 8% ].
If the discrete coefficients are determined to be within the threshold interval, then in sub-step S440, it may be determined that there is no mis-learning. If the discrete coefficients are determined to be outside the threshold interval, then in sub-step S450, it may be determined that there is a mis-learning.
Referring back to fig. 2, if it is determined that there is a mis-learning, the fuel learning value is restored to the previous value in sub-step S250. The dispersion coefficient (V) indicates that the deviation of the air-fuel ratio correction value is excessive outside the threshold interval, and the current fuel learning value is not reasonable, so that it is necessary to return to the previous value (i.e., the value before the time when the fuel learning value is smaller than the fuel limit value). Restoring the previous value may be an iterative process. For example, if the air-fuel ratio correction value (ALPHA) and the actual air-fuel ratio correction value (n) obtained after the first value immediately before the time when the fuel learned value is smaller than the fuel limit value is restored still indicate that there is mis-learning, the fuel learned value may be restored to the second value before the first value. If the second value is not yet satisfied, the restoration to an earlier value may be continued until the restored fuel learning value causes the deviation between the stoichiometric correction value (ALPHA) and the actual air-fuel ratio correction value (n) to be within a reasonable range.
If it is determined that there is no mis-learning, then in sub-step S260, the learning mode is re-entered after a time period T. The deviation of the dispersion coefficient (V) in the threshold interval, which indicates that the air-fuel ratio correction value is within a reasonable range, the current fuel learning value is reasonable and available, so there is no need to return to the previous value, and therefore the learning mode can be restarted after a period of time T.
In some embodiments of the present invention, an air-fuel ratio correction deviation value (σ) may be calculated using a stoichiometric air-fuel ratio correction value (ALPHA) and an actual air-fuel ratio correction value n, where X is a tank volume correction coefficient set according to the volume of the fuel tank, and is preset in a memory. Referring to FIG. 6, a graph is shown in which the correction factor X is related to the volume (i.e., size) of the fuel tank. As an example, the correction factor X may be between 0.8 and 1.2. In this way, the learning delay period (T) can be calculated using the air-fuel ratio correction deviation value (σ): t ═ T × e 0.3σ Where t is a preset learning delay criterion time of the internal combustion engine system. The formula is obtained by combining data obtained by experiments, calculating a trend line after correction according to the drivability requirement and deducing the trend line. Referring to fig. 7, a graph showing the relationship between the deviation value (σ) and the learning prohibited time (i.e., the period T) is shown.
In step S270, the canister relief valve is closed and the canister purge valve is opened. This step may resume the canister purge mode to avoid fuel vapor being vented to the atmosphere. If it was previously determined that there is a mis-learning, the system may repeat the above-described steps S230-S240 after the purge mode is restarted until it is determined that there is no mis-learning.
Alternatively, in the case where the internal combustion engine system is in the learning mode, if the vehicle speed of the vehicle in which the internal combustion engine system is located is close to 0 while the stoichiometric correction value ALPHA is abruptly changed, the learning mode is exited, and the learning mode is reentered when the stoichiometric correction value ALPHA is restored to the level before the abrupt change. Because the fuel injection quantity is large when the vehicle accelerates from a standstill, the ideal air-fuel ratio correction value ALPHA changes abruptly, and does not belong to the content to be learned at the moment, when the situation is detected, the learning is stopped, and after the time period T, the learning is started after the ALPHA value returns to the normal region.
The system for an internal combustion engine and the operating method thereof according to the exemplary embodiment of the present invention are described above. By adopting the system or the method, whether the error learning is caused in the fuel learning mode can be effectively determined, a corresponding control strategy is adopted, and meanwhile, the opening of the purification performance of the carbon tank is considered, so that the problems of fuel vapor odor pollution and the like are avoided.
Fig. 8 shows a time chart of a first example process using the internal combustion engine system and the operation method thereof according to the example embodiment. At time t1, fuel learn value is detected below the fuel limit, learn mode is exited, canister purge valve is closed and canister relief valve is opened to slow the rate of rise of canister pressure and ALPHA. Subsequently, since it is determined that the deviation between the stoichiometric air-fuel ratio correction value ALPHA and the actual air-fuel ratio correction value n is not within the reasonable range (i.e., it is determined that there is a mis-learning), at time t3, the fuel learning value is restored to the previous value, and then the canister relief valve is closed and the canister purge valve is opened, whereby the canister pressure gradually returns to the normal level. At the same time, ALPHA and n are continuously calculated and monitored, and learning is resumed after the deviation between ALPHA and n is within a reasonable range (not shown). As described above, restoring the previous value may be an iterative process, and in FIG. 8, the restoration of the fuel learned value is started at time t2 until the fuel learned value is restored to a reasonable value at time t 3.
Fig. 9 shows a time chart of a second example process using the internal combustion engine system and the operation method thereof according to the example embodiment. At time t1, fuel learn value is detected below the fuel limit, learn mode is exited, canister purge valve is closed and canister relief valve is opened to slow the rate of rise of canister pressure and ALPHA. Subsequently, since it is determined that the deviation between the stoichiometric air-fuel ratio correction value ALPHA and the actual air-fuel ratio correction value n is within a reasonable range (i.e., it is determined that there is no mis-learning and thus there is no need to adjust the current fuel learning value), at time T2, the canister relief valve is closed and the canister purge valve is opened, and the learning mode is re-entered at time T3 after a time period T.
Fig. 10 shows a time chart of a third example process using the internal combustion engine system and the operation method thereof according to the example embodiment. The operations at time t1, time t2, and time t3 are similar to the process described with reference to fig. 9 and will not be described again. As shown in fig. 10, at time t4, the vehicle starts to decelerate gradually to 0, and at time t5, the vehicle starts to restart to cause a sudden change in the ALPHA, and at this time t5 does not belong to what should be learned, so when this is detected, learning should be stopped, and after a delay time elapses, learning is started after the ALPHA value returns to the normal region.
One or more of the techniques and/or embodiments described above may be implemented or included in hardware and/or software, e.g., as modules or means executed on one or more computing devices. Of course, the modules or devices described herein illustrate various functions and are not limited to limiting the structure and function of any embodiment. Rather, the functions of the respective modules or devices may be divided and performed differently by more or less modules or devices according to various design considerations.
Thus far, a system for an internal combustion engine, a method of operating the same, and a medium storing a corresponding program have been described. According to the invention, whether the error learning is caused in the fuel learning mode can be effectively determined, and a corresponding control strategy is adopted, and meanwhile, the opening of the purification performance of the carbon tank is considered, so that the problems of fuel vapor odor pollution and the like are avoided.
Particularly, whether learning and carbon tank purification time need to be matched is determined by monitoring the ALPHA deviation value, so that the problem of gasoline odor is solved by avoiding the occurrence of error learning and simultaneously improving the purification rate of the carbon tank to the maximum extent. While reducing the deviation, robustness will improve and market sigma (fluctuation) will decrease. That is, the exhaust target is relaxed, and therefore the initial cost of the catalyst system can be reduced. In addition, on the basis of the prior art, the opening and closing time of carbon tank purification is judged by utilizing the ALPHA deviation value, more accurate control is realized, the upgrade of the emission standard is better corresponded, and meanwhile, the method can be suitable for the running working condition rather than the idling working condition.
Some exemplary embodiments have been described above. Nevertheless, it will be understood that various modifications may be made to the exemplary embodiments described above without departing from the spirit and scope of the invention. For example, if the described techniques are performed in a different order and/or if components in a described system, architecture, device, or circuit are combined in a different manner and/or replaced or supplemented by additional components or their equivalents, then these modified other implementations are accordingly intended to fall within the scope of the claims.
Claims (15)
1. An operating method for an internal combustion engine system, the internal combustion engine system being in a learning mode, the operating method comprising:
acquiring a fuel learning value;
when the fuel learning value is smaller than the fuel limit value, the learning mode is exited, the carbon tank purification valve is closed, and the carbon tank pressure release valve is opened;
acquiring a pressure value in the carbon tank and an actual air-fuel ratio correction value to calculate an ideal air-fuel ratio correction value;
judging whether there is a mis-learning based on the stoichiometric air-fuel ratio correction value ALPHA and the actual air-fuel ratio correction value n;
restoring the fuel learned value to a previous value in response to determining that there is mis-learning;
re-entering the learning mode after a time period T in response to determining that there is no mis-learning; and
closing the canister relief valve and opening the canister purge valve.
2. The method of operation of claim 1 wherein the fuel limit is determined by:
initially setting the fuel limit value as a system-set lower limit value of a fuel learning value;
continuously monitoring a fuel learning value and a fuel learning value gain; and is
When the gain for N consecutive fuel learned values is negative, the fuel limit is determined using the following equation:
the fuel limit is the current fuel learned value gain (current fuel learned value-previous fuel learned value) + the system set lower limit.
3. The operating method according to claim 1, characterized in that the stoichiometric air-fuel ratio correction value ALPHA is calculated by the following equation:
ALPHA＝n×e C×P ，
where n is an actual air-fuel ratio correction value in the canister purge valve closed state, P is the canister internal pressure value, and C is a constant depending on the remaining fuel percentage of the fuel tank.
4. The method of operation of claim 3, further comprising: and calculating the air-fuel ratio correction deviation value sigma ALPHA X-n, wherein X is a fuel tank volume correction coefficient set according to the volume of the fuel tank.
5. The operating method according to claim 4, wherein the time period T ═ T × e 0.3σ And t is a preset learning delay standard time of the internal combustion engine system.
6. The operating method of claim 1, wherein the step of determining whether there is a mis-learning comprises:
obtaining N ideal air-fuel ratio correction values ALPHA and averaging the correction values ALPHA to obtain an average value ALAVE;
calculating a discrete coefficient between the actual air-fuel ratio correction value n and the average value ALAVE;
determining whether the discrete coefficient is within a threshold interval; and
in response to determining that the discrete coefficients are within a threshold interval, determining that there is no mis-learning; or
In response to determining that the discrete coefficients are outside of a threshold interval, determining that a mis-learning exists.
7. The operating method according to claim 1, characterized in that, in the case where the internal combustion engine system is in the learning mode, if the vehicle speed of the vehicle in which the internal combustion engine system is located increases from 0 while the stoichiometric air-fuel ratio correction value ALPHA abruptly changes, the learning mode is exited, and the learning mode is reentered after the time period T.
8. A system for an internal combustion engine, the system comprising:
a canister that captures fuel vapor generated from the fuel tank;
a canister purge valve that supplies fuel vapor in the canister to an intake pipe of an internal combustion engine when opened;
a canister relief valve that releases fuel vapor within the canister to atmosphere when opened; and
a control unit, the control unit comprising:
a memory for storing data relating to the canister and the internal combustion engine, wherein the data includes a fuel learning value, a pressure value within the canister, and an actual air-fuel ratio correction value; and
a processor to perform the following when the system is in a learn mode and the canister purge valve is open:
acquiring a fuel learning value;
when the fuel learning value is smaller than a fuel limit value, exiting the learning mode, closing the carbon tank purification valve and opening the carbon tank pressure release valve;
acquiring a pressure value in the carbon tank and an actual air-fuel ratio correction value to calculate an ideal air-fuel ratio correction value;
determining whether there is a mis-learning based on the stoichiometric air-fuel ratio correction value and the actual air-fuel ratio correction value;
restoring the fuel learned value to a previous value in response to determining that there is mis-learning;
re-entering the learning mode after a period of time in response to determining that there is no mis-learning; and
closing the canister relief valve and opening the canister purge valve.
9. The system of claim 8, wherein the fuel limit is determined by:
initially setting the fuel limit value as a system-set lower limit value of a fuel learning value;
continuously monitoring a fuel learning value and a fuel learning value gain; and is
When the gain for N consecutive fuel learned values is negative, the fuel limit is determined using the following equation:
the fuel limit is the current fuel learned value gain (current fuel learned value-previous fuel learned value) + the system set lower limit.
10. The system according to claim 8, wherein the stoichiometric correction value ALPHA is calculated by the following equation:
ALPHA＝n×e C×P ，
where n is the actual air-fuel ratio correction value with the canister purge valve closed, P is the canister internal pressure value, and C is a constant dependent on the percentage of fuel remaining in the fuel tank.
11. The system of claim 10, wherein said processor further calculates said air-fuel ratio correction offset σ ═ ALPHA X-n, where X is a tank volume correction factor set based on the volume of said fuel tank.
12. The system of claim 11, wherein the time period T ═ txe 0.3σ Wherein t is a default learning standard time of the internal combustion engine system.
13. The system of claim 8, wherein the operation of determining whether there is a mis-learning comprises:
obtaining N ideal air-fuel ratio correction values ALPHA and averaging the correction values ALPHA to obtain an average value ALAVE;
calculating a discrete coefficient between the actual air-fuel ratio correction value n and the average value ALAVE;
determining whether the discrete coefficient is within a threshold interval; and
in response to determining that the discrete coefficients are within a threshold interval, determining that there is no mis-learning; or
In response to determining that the discrete coefficients are outside of a threshold interval, determining that a mis-learning exists.
14. The system according to claim 8, characterized in that, in the case where the system is in the learning mode, if the vehicle speed of the vehicle in which the system is located increases from 0 while the stoichiometric air-fuel ratio correction value ALPHA abruptly changes, the learning mode is exited, and the learning mode is reentered after the time period T.
15. A computer-readable storage medium, on which a computer program is stored which, when being executed by a processor, carries out the method according to any one of claims 1-7.
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Citations (7)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JPH07247920A (en) * | 1994-03-09 | 1995-09-26 | Fuji Heavy Ind Ltd | Canister purge control |
| CN103670816A (en) * | 2012-09-12 | 2014-03-26 | 北汽福田汽车股份有限公司 | Control device and method for desorption of carbon tank and carbon tank desorption control system |
| CN107542589A (en) * | 2016-06-27 | 2018-01-05 | 丰田自动车株式会社 | The method of the A/F ratio controller of internal combustion engine and the air-fuel ratio for controlling internal combustion engine |
| CN107776397A (en) * | 2016-08-29 | 2018-03-09 | 长城汽车股份有限公司 | Fuel oil gas recovery system for oil |
| CN109667679A (en) * | 2017-10-16 | 2019-04-23 | 现代自动车株式会社 | The method and apparatus of engine are controlled during the idling cleaning of canister |
| CN110805498A (en) * | 2019-11-11 | 2020-02-18 | 奇瑞汽车股份有限公司 | Engine fuel correction control method |
| CN111156099A (en) * | 2018-11-08 | 2020-05-15 | 爱三工业株式会社 | Internal combustion engine system |
-
2021
- 2021-03-15 CN CN202110275710.5A patent/CN115075970A/en active Pending
Patent Citations (7)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JPH07247920A (en) * | 1994-03-09 | 1995-09-26 | Fuji Heavy Ind Ltd | Canister purge control |
| CN103670816A (en) * | 2012-09-12 | 2014-03-26 | 北汽福田汽车股份有限公司 | Control device and method for desorption of carbon tank and carbon tank desorption control system |
| CN107542589A (en) * | 2016-06-27 | 2018-01-05 | 丰田自动车株式会社 | The method of the A/F ratio controller of internal combustion engine and the air-fuel ratio for controlling internal combustion engine |
| CN107776397A (en) * | 2016-08-29 | 2018-03-09 | 长城汽车股份有限公司 | Fuel oil gas recovery system for oil |
| CN109667679A (en) * | 2017-10-16 | 2019-04-23 | 现代自动车株式会社 | The method and apparatus of engine are controlled during the idling cleaning of canister |
| CN111156099A (en) * | 2018-11-08 | 2020-05-15 | 爱三工业株式会社 | Internal combustion engine system |
| CN110805498A (en) * | 2019-11-11 | 2020-02-18 | 奇瑞汽车股份有限公司 | Engine fuel correction control method |
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