CN117703610A - EGR rate control method and device, vehicle and storage medium - Google Patents
EGR rate control method and device, vehicle and storage medium Download PDFInfo
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- QVGXLLKOCUKJST-UHFFFAOYSA-N atomic oxygen Chemical compound [O] QVGXLLKOCUKJST-UHFFFAOYSA-N 0.000 claims abstract description 302
- 239000001301 oxygen Substances 0.000 claims abstract description 302
- 229910052760 oxygen Inorganic materials 0.000 claims abstract description 302
- 239000007789 gas Substances 0.000 claims description 52
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- MWUXSHHQAYIFBG-UHFFFAOYSA-N nitrogen oxide Inorganic materials O=[N] MWUXSHHQAYIFBG-UHFFFAOYSA-N 0.000 description 3
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Abstract
The invention discloses an EGR rate control method, an EGR rate control device, a vehicle and a storage medium. The EGR rate control method includes: when the current engine working condition is confirmed to be in a stable state, a first EGR rate, a second EGR rate, a first engine air inflow and a first engine exhaust amount are obtained, and a first oxygen concentration and a second oxygen concentration are obtained; determining an actual oxygen concentration difference based on the first oxygen concentration and the second oxygen concentration, and determining a first theoretical oxygen concentration value based on the first oxygen concentration, the first EGR rate, the second EGR rate, the first engine intake air amount, and the first engine exhaust air amount; and determining whether the second EGR rate control is correct according to the actual oxygen concentration difference value and the first theoretical oxygen concentration value, and judging whether the second EGR rate is adjusted according to the second oxygen concentration after determining that the second EGR rate control is correct. The invention realizes the verification of whether the EGR rate is correct or not based on the oxygen concentration, and can carry out closed-loop control on the EGR rate.
Description
Technical Field
The present invention relates to the field of engine control technologies, and in particular, to an EGR rate control method, an EGR rate control device, a vehicle, and a storage medium.
Background
EGR (exhaust gas Recirculation ) is an inboard purification technique for reducing NO in diesel and gasoline engines X One of the effective means of emission and one of the effective means of reducing fuel consumption at the same time, but increasing the EGR rate can lead to faster rise of the exhaust emission of diesel engine soot, and reasonable control of the EGR rateThe purifying effect of nitrogen oxides and the discharge of the whole machine are extremely important.
The current EGR rate calculation method is calculated by using the ratio of the exhaust gas recirculation flow calculated by the venturi tube and the Bernoulli equation to the total air intake total amount of the engine, wherein the total air intake total amount of the engine is calculated by using the speed density method based on an ideal gas equation, the exhaust gas flow is calculated by using the venturi tube and the Bernoulli equation, and the calculated value is used for comparison, so that the result obtained by comparison is considered to be the actual EGR rate, but the EGR rate does not form a closed loop, and whether the current EGR actual rate is correct or not can not be determined.
Disclosure of Invention
The invention provides an EGR rate control method, an EGR rate control device, a vehicle and a storage medium, which are used for solving the problems that whether the calculated EGR rate is correct or not and the EGR rate cannot be flexibly controlled at the same time.
According to an aspect of the present invention, there is provided an EGR rate control method including:
when the current engine working condition is confirmed to be in a stable state, a first EGR rate, a second EGR rate, a first engine air inflow corresponding to the first EGR rate and a first engine exhaust gas amount are obtained, and a first oxygen concentration detected by a feed-forward oxygen sensor under the control of the first EGR rate and a second oxygen concentration detected by the feed-forward oxygen sensor under the control of the second EGR rate are obtained;
determining an actual oxygen concentration difference from the first oxygen concentration and the second oxygen concentration, and determining a first theoretical oxygen concentration value from the first oxygen concentration, the first EGR rate, the second EGR rate, the first engine intake air amount, and the first engine exhaust gas amount;
and determining whether the second EGR rate control is correct according to the actual oxygen concentration difference value and the first theoretical oxygen concentration value, and judging whether to adjust the second EGR rate according to the second oxygen concentration after determining that the second EGR rate control is correct.
Optionally, the first EGR rate is less than the second EGR rate;
determining an actual oxygen concentration difference from the first oxygen concentration and the second oxygen concentration, comprising:
and subtracting the first oxygen concentration from the second oxygen concentration to obtain an oxygen concentration as an actual oxygen concentration difference.
Optionally, determining a first theoretical oxygen concentration value according to the first oxygen concentration, the first EGR rate, the second EGR rate, the first engine intake air amount, and the first engine exhaust gas amount includes:
the first theoretical oxygen concentration value is determined according to the following formula:
m 1 ·Δγ＝m 2 ·(β-α)·(21％-γ1)
wherein Δγ1 is the first theoretical oxygen concentration value; alpha is the first EGR rate; beta is the second EGR rate; γ1 is the first oxygen concentration; m is m 1 Exhausting the first engine amount; m is m 2 An intake air amount for the first engine.
Optionally, determining whether the second EGR rate control is correct according to the actual oxygen concentration difference and the first theoretical oxygen concentration value includes:
determining an EGR rate control judgment range according to the first theoretical oxygen concentration value;
if the actual oxygen concentration difference value is in the EGR rate control judgment range, determining that the second EGR rate is correctly controlled;
and if the actual oxygen concentration difference value is not in the EGR rate control judgment range, determining that the second EGR rate control is wrong.
Optionally, before determining whether to adjust the second EGR rate according to the second oxygen concentration, the method further includes:
and acquiring a second engine air inflow and a second engine exhaust gas amount corresponding to the second EGR rate, and determining a second theoretical oxygen concentration value according to the second oxygen concentration, the first EGR rate, the second engine air inflow and the second engine exhaust gas amount.
Optionally, determining whether to adjust the second EGR rate according to the second oxygen concentration includes:
if the second oxygen concentration is higher than the second theoretical oxygen concentration value, increasing the second EGR rate;
and if the second oxygen concentration is lower than the second theoretical oxygen concentration value, reducing the second EGR rate.
Optionally, after increasing the second EGR rate, the method further includes:
acquiring an updated EGR rate, and acquiring an updated oxygen concentration detected by a feed-forward oxygen sensor under control of the updated EGR rate, the updated EGR rate being greater than the second EGR rate;
determining an updated actual oxygen concentration difference based on the second oxygen concentration and the updated oxygen concentration, and determining an updated theoretical oxygen concentration value based on the second oxygen concentration, the second EGR rate, the updated EGR rate, the second engine intake air amount, and the second engine exhaust gas amount;
and determining whether the updated EGR rate control is correct according to the updated actual oxygen concentration difference value and the updated theoretical oxygen concentration value.
According to another aspect of the present invention, there is provided an EGR rate control apparatus including:
the data acquisition module is used for acquiring a first EGR rate, a second EGR rate, a first engine air inflow corresponding to the first EGR rate and a first engine exhaust gas amount when the current engine working condition is confirmed to be in a stable state, and acquiring a first oxygen concentration detected by a feed-forward oxygen sensor under the control of the first EGR rate and a second oxygen concentration detected by the feed-forward oxygen sensor under the control of the second EGR rate;
an oxygen concentration value determination module that performs determination of an actual oxygen concentration difference based on the first oxygen concentration and the second oxygen concentration, and determines a first theoretical oxygen concentration value based on the first oxygen concentration, the first EGR rate, the second EGR rate, the first engine intake air amount, and the first engine exhaust air amount;
and the EGR rate control module is used for determining whether the second EGR rate control is correct according to the actual oxygen concentration difference value and the first theoretical oxygen concentration value, and judging whether the second EGR rate is adjusted according to the second oxygen concentration after determining that the second EGR rate control is correct.
According to another aspect of the present invention, there is provided a vehicle including:
at least one processor; the method comprises the steps of,
a memory communicatively coupled to the at least one processor; wherein,
the memory stores a computer program executable by the at least one processor to enable the at least one processor to perform the EGR rate control method according to any of the embodiments of the present invention.
According to another aspect of the present invention, there is provided a computer readable storage medium storing computer instructions for causing a processor to execute the EGR rate control method according to any of the embodiments of the present invention.
According to the technical scheme, when the current engine working condition is confirmed to be in a stable state, a first EGR rate, a second EGR rate, a first engine air inflow corresponding to the first EGR rate and a first engine exhaust gas amount are obtained, and a first oxygen concentration detected by a feed-forward oxygen sensor under control of the first EGR rate and a second oxygen concentration detected by the feed-forward oxygen sensor under control of the second EGR rate are obtained; determining an actual oxygen concentration difference from the first oxygen concentration and the second oxygen concentration, and determining a first theoretical oxygen concentration value from the first oxygen concentration, the first EGR rate, the second EGR rate, the first engine intake air amount, and the first engine exhaust gas amount; and determining whether the second EGR rate control is correct according to the actual oxygen concentration difference value and the first theoretical oxygen concentration value, and judging whether to adjust the second EGR rate according to the second oxygen concentration after determining that the second EGR rate control is correct. The invention solves the problems that whether the calculated EGR rate is correct or not and the EGR rate cannot be flexibly controlled, realizes the verification of whether the EGR rate is correct or not based on the oxygen concentration, and can carry out closed-loop control on the EGR rate.
It should be understood that the description in this section is not intended to identify key or critical features of the embodiments of the invention or to delineate the scope of the invention. Other features of the present invention will become apparent from the description that follows.
Drawings
In order to more clearly illustrate the technical solutions of the embodiments of the present invention, the drawings required for the description of the embodiments will be briefly described below, and it is apparent that the drawings in the following description are only some embodiments of the present invention, and other drawings may be obtained according to these drawings without inventive effort for a person skilled in the art.
FIG. 1 is a flow chart of an EGR rate control method provided in accordance with a first embodiment of the present invention;
fig. 2 is a flowchart of an EGR rate control method according to the second embodiment of the present invention;
FIG. 3 is a prior art engine air circuit diagram provided in accordance with an embodiment of the present invention;
fig. 4 is a schematic structural view of an EGR rate control device according to the third embodiment of the present invention;
fig. 5 is a schematic structural diagram of a vehicle implementing an EGR rate control method according to an embodiment of the present invention.
Detailed Description
In order that those skilled in the art will better understand the present invention, a technical solution in the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings in which it is apparent that the described embodiments are only some embodiments of the present invention, not all embodiments. All other embodiments, which can be made by those skilled in the art based on the embodiments of the present invention without making any inventive effort, shall fall within the scope of the present invention.
It should be noted that the terms "first," "second," and the like in the description and the claims of the present invention and the above figures are used for distinguishing between similar objects and not necessarily for describing a particular sequential or chronological order. It is to be understood that the data so used may be interchanged where appropriate such that the embodiments of the invention described herein may be implemented in sequences other than those illustrated or otherwise described herein. Furthermore, the terms "comprises," "comprising," and "having," and any variations thereof, are intended to cover a non-exclusive inclusion, such that a process, method, system, article, or apparatus that comprises a list of steps or elements is not necessarily limited to those steps or elements expressly listed but may include other steps or elements not expressly listed or inherent to such process, method, article, or apparatus.
Example 1
Fig. 1 is a flowchart of an EGR rate control method according to an embodiment of the present invention, which is applicable to a case where an EGR rate is closed-loop controlled based on an exhaust gas oxygen concentration, and the EGR rate control method may be performed by an EGR rate control device that may be implemented in hardware and/or software, and may be configured in various vehicles. As shown in fig. 1, the EGR rate control method includes:
s110, when the current engine working condition is confirmed to be in a stable state, a first EGR rate, a second EGR rate, a first engine air inflow corresponding to the first EGR rate and a first engine exhaust gas amount are obtained, and a first oxygen concentration detected by a feed-forward oxygen sensor under control of the first EGR rate and a second oxygen concentration detected by the feed-forward oxygen sensor under control of the second EGR rate are obtained.
Wherein, confirming that the current engine working condition is in a stable state can refer to confirming that the current vehicle is in a stable speed, and it can be understood that the speed is stable within an acceptable fluctuation range, and the current engine working condition is considered to be in a stable state when the speed is 80km/h-85 km/h; on the other hand, confirming that the current engine condition is in a stable state may refer to the stabilization of parameters such as engine speed, fuel injection amount, engine air intake amount, fuel consumption amount, etc., and it is understood that parameters such as engine speed, fuel injection amount, engine air intake amount, fuel consumption amount, etc., are also stabilized within acceptable fluctuation ranges.
The EGR rate is a ratio of the recirculation amount of exhaust gas in the gas entering the cylinder, and the EGR rate, specifically, the EGR rate= [ EGR amount/(intake air amount+egr amount) ], is 100% can be calculated by a formula. It will be appreciated that the first EGR rate may be calculated by the above equation, or may be calculated by other means, and this embodiment is not particularly limited.
The first EGR rate is obtained in real time when the current engine working condition is confirmed to be in a stable state, the second EGR rate is set by considering that the EGR rate needs to be increased when the current engine working condition is confirmed to be in the stable state, and the second EGR rate can be set by the self selection of a person skilled in the art or automatically recognized by a vehicle, and is larger than the first EGR rate, and the first EGR rate is larger than or equal to 0.
The first engine intake air amount and the first engine exhaust gas amount corresponding to the first EGR rate may be calculated by, but not limited to, existing formulas, where the first engine intake air amount and the first engine exhaust gas amount are engine intake air amounts when the current engine operating condition is confirmed to be in a steady state, and optionally, engine intake air amount=rotation speed×exhaust gas amount×volumetric efficiency/3456.
In this embodiment, considering whether the EGR rate control is correct based on the oxygen concentration in the exhaust gas, and implementing closed-loop control on the EGR rate, the first oxygen concentration is detected in real time by the feed-forward oxygen sensor under the first EGR rate control, and the second oxygen concentration is detected in real time by the feed-forward oxygen sensor under the second EGR rate control.
S120, determining an actual oxygen concentration difference value according to the first oxygen concentration and the second oxygen concentration, and determining a first theoretical oxygen concentration value according to the first oxygen concentration, the first EGR rate, the second EGR rate, the first engine air inflow and the first engine exhaust gas amount.
Specifically, the oxygen concentration obtained by subtracting the first oxygen concentration from the second oxygen concentration is used as the actual oxygen concentration difference.
In this embodiment, the oxygen concentration in the exhaust gas discharged from the engine is mainly dependent on the mass of fresh intake air of the engine and the consumption of combustion in the engine cylinder, and the oxygen amount normally consumed is basically a constant value under the condition of keeping the working condition unchanged, at this time, the oxygen content in the exhaust gas discharged is mainly determined by the mass m12 of intake air of the engine, and since the working condition of the current engine is constant, the total amount of intake air of the engine can be considered to be constant, thereby deducing that the change of the concentration delta gamma of oxygen in the exhaust gas discharged when the EGR rate is increased from the first EGR rate alpha to the second EGR rate beta satisfies the following formula, specifically:
m 1 ·Δγ＝m 2 ·(β-α)·(21％-γ1)
wherein Δγ1 is the first theoretical oxygen concentration value; alpha is the first EGR rate; beta is the second EGR rate; γ1 is the first oxygen concentration; m is m 1 Exhausting the first engine amount; m is m 2 An intake air amount for the first engine.
It is known that m 1 Δγ represents a change in oxygen concentration caused by a decrease in engine intake air amount; m is m 2 (beta-alpha) represents the mass of decrease in the intake air amount of the fresh engine caused by the change in the EGR rate; 21% - γ represents the difference in oxygen concentration between the fresh engine intake and exhaust (assuming here that the oxygen content in air is 21%), typically Δγ is much smaller than γ, and can be deduced as γζ γ± Δγ.
S130, determining whether the second EGR rate control is correct according to the actual oxygen concentration difference value and the first theoretical oxygen concentration value, and judging whether the second EGR rate is adjusted according to the second oxygen concentration after determining that the second EGR rate control is correct.
Specifically, the EGR rate control determination range is determined according to the first theoretical oxygen concentration value, and the EGR rate control determination range is determined by using the first theoretical oxygen concentration value with a selectable multiple value, and the EGR rate control determination range is exemplified by 0.8 x the first theoretical oxygen concentration value to 1.2 x the first theoretical oxygen concentration value, which may also be selected and set by a person skilled in the art according to actual needs, and this embodiment is not limited in any way.
On the basis of the above, exemplary, if the actual oxygen concentration difference is between 0.8 x the first theoretical oxygen concentration value and 1.2 x the first theoretical oxygen concentration value, it is determined that the second EGR rate is controlled correctly; and if the actual oxygen concentration difference is not between 0.8 and 1.2, determining that the second EGR rate is controlled incorrectly.
If the second EGR rate is determined to be correctly controlled, executing subsequent closed-loop control at the second EGR rate; and if the second EGR rate control error is determined, reporting an EGR rate control abnormal fault.
On the basis of the above embodiment, after determining that the second EGR rate is controlled correctly, a second engine intake air amount and a second engine exhaust gas amount corresponding to the second EGR rate are obtained, and a second theoretical oxygen concentration value is determined according to the second oxygen concentration, the first EGR rate, the second engine intake air amount, and the second engine exhaust gas amount.
Further, if the second oxygen concentration is higher than the second theoretical oxygen concentration value, increasing the second EGR rate; and if the second oxygen concentration is lower than the second theoretical oxygen concentration value, reducing the second EGR rate.
Specifically, after the second EGR rate is determined to be controlled correctly, closed-loop control of the EGR rate is achieved based on the oxygen concentration, that is, a relationship between the second oxygen concentration and a second theoretical oxygen concentration value is determined, and when the second oxygen concentration is higher than the second theoretical oxygen concentration value, the EGR rate can be continuously increased, and when the second oxygen concentration is lower than the second theoretical oxygen concentration value, the EGR rate can be appropriately reduced, so that the closed-loop control of the EGR rate can be achieved through the method.
According to the technical scheme, when the current engine working condition is confirmed to be in a stable state, a first EGR rate, a second EGR rate, a first engine air inflow corresponding to the first EGR rate and a first engine exhaust gas amount are obtained, and a first oxygen concentration detected by a feed-forward oxygen sensor under control of the first EGR rate and a second oxygen concentration detected by the feed-forward oxygen sensor under control of the second EGR rate are obtained; determining an actual oxygen concentration difference from the first oxygen concentration and the second oxygen concentration, and determining a first theoretical oxygen concentration value from the first oxygen concentration, the first EGR rate, the second EGR rate, the first engine intake air amount, and the first engine exhaust gas amount; and determining whether the second EGR rate control is correct according to the actual oxygen concentration difference value and the first theoretical oxygen concentration value, and judging whether to adjust the second EGR rate according to the second oxygen concentration after determining that the second EGR rate control is correct. The invention solves the problems that whether the calculated EGR rate is correct or not and the EGR rate cannot be flexibly controlled, realizes the verification of whether the EGR rate is correct or not based on the oxygen concentration, and can carry out closed-loop control on the EGR rate.
Example two
Fig. 2 is a flowchart of an EGR rate control method according to a second embodiment of the present invention, and an alternative implementation manner is provided according to this embodiment and on the basis of the foregoing embodiments. As shown in fig. 2, the EGR rate control method includes:
s210, when the current engine working condition is confirmed to be in a stable state, a first EGR rate, a second EGR rate, a first engine air inflow corresponding to the first EGR rate and a first engine exhaust gas amount are obtained, and a first oxygen concentration detected by a feed-forward oxygen sensor under control of the first EGR rate and a second oxygen concentration detected by the feed-forward oxygen sensor under control of the second EGR rate are obtained.
S220, subtracting the first oxygen concentration from the second oxygen concentration to obtain an oxygen concentration as an actual oxygen concentration difference.
S230, determining a first theoretical oxygen concentration value according to the first oxygen concentration, the first EGR rate, the second EGR rate, the first engine air inflow and the first engine exhaust gas amount.
S240, determining an EGR rate control judgment range according to the first theoretical oxygen concentration value, judging whether the actual oxygen concentration difference value is in the EGR rate control judgment range, if so, executing step S250, and if not, executing step S260.
And S250, if the second EGR rate is determined to be controlled correctly, executing step S270.
S260, determining the second EGR rate control error.
S270, obtaining a second engine air inflow and a second engine exhaust gas amount corresponding to the second EGR rate, and determining a second theoretical oxygen concentration value according to the second oxygen concentration, the first EGR rate, the second engine air inflow and the second engine exhaust gas amount.
S280, judging whether the second oxygen concentration is higher than the second theoretical oxygen concentration value, if so, executing a step S281, and if not, executing a step S282.
S281, increasing the second EGR rate.
S282, reducing the second EGR rate.
On the basis of the above, as shown in fig. 3, when the EGR rate is considered to be increased from the first EGR rate α to the second EGR rate β in the present embodiment, the intake-exhaust mass relationship is established in combination with the oxygen concentration according to the mass conservation law, and the specific mass conservation law is:
m 1 ＝m 21 +m 11
m 2 +m f ＝m 21 +m 11 ＝m 1
wherein m is 1 Total displacement for the engine 31; m is m 21 Exhaust gas that is not recirculated directly into the aftertreatment system for the total displacement of the engine 31; m is m 11 Mass flow of exhaust gas recirculation gas through EGR 32 for the total displacement of engine 31; m is m 2 The total intake air amount for the engine 31; m is m f Is a change in the intake air amount due to fluctuation of injection of the engine 31.
According to the above conditions, the change of the EGR rate can be actively controlled when the working condition of the engine is stable and unchanged, when the EGR rate is changed according to a formula for determining the first theoretical oxygen concentration value, the accurate oxygen concentration difference value can be calculated according to the oxygen concentration signal detected by the feedforward oxygen sensor and the intake and exhaust quality formula, and whether the EGR rate is correct can be judged by comparing the calculated concentration difference value with the oxygen concentration before and after the change of the EGR rate. And similarly, the reverse thrust is performed, after the EGR rate is increased, the concentration of oxygen detected by the oxygen sensor is larger than the theoretical value, so that the EGR rate can be continuously increased, and if the EGR rate is increased, the concentration detected by the oxygen sensor is lower than the theoretical value, the EGR rate can be properly reduced, so that the closed-loop control of the EGR rate based on the oxygen concentration is realized.
On the basis of the above-described embodiments, in one embodiment, after increasing the second EGR rate, an updated EGR rate is obtained, and an updated oxygen concentration detected by a feed-forward oxygen sensor under control of the updated EGR rate is obtained, the updated EGR rate being greater than the second EGR rate; determining an updated actual oxygen concentration difference based on the second oxygen concentration and the updated oxygen concentration, and determining an updated theoretical oxygen concentration value based on the second oxygen concentration, the second EGR rate, the updated EGR rate, the second engine intake air amount, and the second engine exhaust gas amount; and determining whether the updated EGR rate control is correct according to the updated actual oxygen concentration difference value and the updated theoretical oxygen concentration value.
The updated EGR rate may be set by a person skilled in the art or automatically identified by the vehicle, where the updated EGR rate is greater than the second EGR rate, and the updated EGR rate is determined to be controlled correctly according to the updated oxygen concentration detected by the feed-forward oxygen sensor under the updated EGR rate control, where the specific determination mode is the same as the above determination mode.
It is to be understood that the second engine intake air amount and the second engine exhaust gas amount corresponding to the second EGR rate at this time are, as values for determining the updated theoretical oxygen concentration value, specifically:
m 1 ′·Δγ′＝m 2 ′·(γ-β)·(21％-γ1′)
wherein Δγ1' is the updated theoretical oxygen concentration value; gamma is the updated EGR rate; beta is the second EGR rate; γ1' is the second oxygen concentration; m is m 1 ' is the second engine displacement; m is m 2 ' is the second engine intake air amount.
Similarly, in an embodiment, after the second EGR rate is reduced, a new updated EGR rate is obtained as well, and the same procedure as described above is used to determine whether the new updated EGR rate is correct, so that closed-loop control of the EGR rate is achieved, and is not described again.
Most existing EGR rate calculation methods are estimated by using the ratio of the flow of exhaust gas recirculation to the total intake air amount of the engine, but the estimated EGR rate is not checked correctly, and whether the currently calculated EGR rate has deviation cannot be determined. The technical means of the embodiment of the invention establishes the relationship between the EGR rate and the oxygen concentration under the working condition of the stable engine, and verifies whether the EGR rate is correct or not by utilizing the oxygen concentration so as to realize closed-loop control of the EGR. In addition, if the oxygen concentration detected by the oxygen concentration sensor is higher than the theoretically calculated oxygen concentration after the EGR rate is increased, the EGR rate may be continuously increased, and if the oxygen concentration detected by the oxygen concentration sensor is lower than the theoretically calculated oxygen concentration value after the EGR rate is increased, the EGR rate may be appropriately decreased, and by this means, closed-loop control of the EGR rate may be achieved.
Example III
Fig. 4 is a schematic structural diagram of an EGR rate control device according to a third embodiment of the present invention. As shown in fig. 4, the EGR rate control device includes:
a data acquisition module 310, configured to acquire a first EGR rate, a second EGR rate, and a first engine intake air amount and a first engine exhaust gas amount corresponding to the first EGR rate when it is determined that a current engine operating condition is in a steady state, and acquire a first oxygen concentration detected by a feed-forward oxygen sensor under control of the first EGR rate and a second oxygen concentration detected by the feed-forward oxygen sensor under control of the second EGR rate;
an oxygen concentration value determination module 320 for performing determination of an actual oxygen concentration difference based on the first oxygen concentration and the second oxygen concentration, and determining a first theoretical oxygen concentration value based on the first oxygen concentration, the first EGR rate, the second EGR rate, the first engine intake air amount, and the first engine exhaust gas amount;
and an EGR rate control module 330 configured to determine whether the second EGR rate control is correct according to the actual oxygen concentration difference and the first theoretical oxygen concentration value, and determine whether to adjust the second EGR rate according to the second oxygen concentration after determining that the second EGR rate control is correct.
Optionally, the first EGR rate is less than the second EGR rate;
determining an actual oxygen concentration difference from the first oxygen concentration and the second oxygen concentration, in particular for:
and subtracting the first oxygen concentration from the second oxygen concentration to obtain an oxygen concentration as an actual oxygen concentration difference.
Optionally, a first theoretical oxygen concentration value is determined according to the first oxygen concentration, the first EGR rate, the second EGR rate, the first engine intake air amount, and the first engine exhaust gas amount, specifically for:
the first theoretical oxygen concentration value is determined according to the following formula:
m 1 ·Δγ＝m 2 ·(β-α)·(21％-γ1)
wherein Δγ1 is the first theoretical oxygen concentration value; alpha is the first EGR rate; beta is the second EGR rate; γ1 is the first oxygen concentration; m is m 1 Exhausting the first engine amount; m is m 2 An intake air amount for the first engine.
Optionally, determining whether the second EGR rate control is correct according to the actual oxygen concentration difference and the first theoretical oxygen concentration value is specifically configured to:
determining an EGR rate control judgment range according to the first theoretical oxygen concentration value;
if the actual oxygen concentration difference value is in the EGR rate control judgment range, determining that the second EGR rate is correctly controlled;
and if the actual oxygen concentration difference value is not in the EGR rate control judgment range, determining that the second EGR rate control is wrong.
Optionally, the EGR rate control device further includes:
and the second theoretical oxygen concentration value determining module is used for executing the acquisition of a second engine air inflow and a second engine exhaust gas amount corresponding to the second EGR rate and determining a second theoretical oxygen concentration value according to the second oxygen concentration, the first EGR rate, the second engine air inflow and the second engine exhaust gas amount.
Optionally, determining whether to adjust the second EGR rate according to the second oxygen concentration is specifically configured to:
if the second oxygen concentration is higher than the second theoretical oxygen concentration value, increasing the second EGR rate;
and if the second oxygen concentration is lower than the second theoretical oxygen concentration value, reducing the second EGR rate.
Optionally, the EGR rate control device further includes:
acquiring an updated EGR rate, and acquiring an updated oxygen concentration detected by a feed-forward oxygen sensor under control of the updated EGR rate, the updated EGR rate being greater than the second EGR rate;
determining an updated actual oxygen concentration difference based on the second oxygen concentration and the updated oxygen concentration, and determining an updated theoretical oxygen concentration value based on the second oxygen concentration, the second EGR rate, the updated EGR rate, the second engine intake air amount, and the second engine exhaust gas amount;
and determining whether the updated EGR rate control is correct according to the updated actual oxygen concentration difference value and the updated theoretical oxygen concentration value.
The EGR rate control device provided by the embodiment of the invention can execute the EGR rate control method provided by any embodiment of the invention, and has the corresponding functional modules and beneficial effects of executing the EGR rate control method.
Example IV
Fig. 5 shows a schematic structural diagram of a vehicle 410 that may be used to implement an embodiment of the invention. Vehicles include digital computers intended to represent various forms, such as laptops, desktops, workstations, personal digital assistants, servers, blade servers, mainframes, and other appropriate computers. The vehicle may also include a device representing various forms of mobile devices, such as personal digital assistants, cellular telephones, smart phones, wearable devices (e.g., helmets, glasses, watches, etc.), and other similar computing devices. The components shown herein, their connections and relationships, and their functions, are meant to be exemplary only, and are not meant to limit implementations of the inventions described and/or claimed herein.
As shown in fig. 5, the vehicle 410 includes at least one processor 411, and a memory, such as a read only memory (ROM 412), a random access memory (RAM 413), etc., communicatively connected to the at least one processor 411, wherein the memory stores computer programs executable by the at least one processor, and the processor 411 can perform various suitable actions and processes according to the computer programs stored in the read only memory (ROM 412) or the computer programs loaded from the storage unit 418 into the random access memory (RAM 413). In the RAM 413, various programs and data required for the operation of the vehicle 410 may also be stored. The processor 411, the ROM 412, and the RAM 413 are connected to each other through a bus 414. An I/O (input/output) interface 415 is also connected to bus 414.
Various components in the vehicle 410 are connected to the I/O interface 415, including: an input unit 416 such as a keyboard, a mouse, etc.; an output unit 417 such as various types of displays, speakers, and the like; a storage unit 418, such as a magnetic disk, optical disk, or the like; and a communication unit 419 such as a network card, modem, wireless communication transceiver, etc. The communication unit 419 allows the vehicle 410 to exchange information/data with other devices through a computer network such as the internet and/or various telecommunication networks.
The processor 411 may be a variety of general and/or special purpose processing components having processing and computing capabilities. Some examples of processor 411 include, but are not limited to, a Central Processing Unit (CPU), a Graphics Processing Unit (GPU), various specialized Artificial Intelligence (AI) computing chips, various processors running machine learning model algorithms, digital Signal Processors (DSPs), and any suitable processor, controller, microcontroller, etc. The processor 411 executes the various methods and processes described above, such as an EGR rate control method.
In some embodiments, the EGR rate control method may be implemented as a computer program tangibly embodied on a computer-readable storage medium, such as storage unit 418. In some embodiments, some or all of the computer program may be loaded and/or installed onto the vehicle 410 via the ROM 412 and/or the communication unit 419. When a computer program is loaded into RAM 413 and executed by processor 411, one or more steps of the EGR rate control method described above may be performed. Alternatively, in other embodiments, the processor 411 may be configured to perform the EGR rate control method in any other suitable manner (e.g., by means of firmware).
Various implementations of the systems and techniques described here above may be implemented in digital electronic circuitry, integrated circuit systems, field Programmable Gate Arrays (FPGAs), application Specific Integrated Circuits (ASICs), application Specific Standard Products (ASSPs), systems On Chip (SOCs), load programmable logic devices (CPLDs), computer hardware, firmware, software, and/or combinations thereof. These various embodiments may include: implemented in one or more computer programs, the one or more computer programs may be executed and/or interpreted on a programmable system including at least one programmable processor, which may be a special purpose or general-purpose programmable processor, that may receive data and instructions from, and transmit data and instructions to, a storage system, at least one input device, and at least one output device.
A computer program for carrying out methods of the present invention may be written in any combination of one or more programming languages. These computer programs may be provided to a processor of a general purpose computer, special purpose computer, or other programmable data processing apparatus, such that the computer programs, when executed by the processor, cause the functions/acts specified in the flowchart and/or block diagram block or blocks to be implemented. The computer program may execute entirely on the machine, partly on the machine, as a stand-alone software package, partly on the machine and partly on a remote machine or entirely on the remote machine or server.
In the context of the present invention, a computer-readable storage medium may be a tangible medium that can contain, or store a computer program for use by or in connection with an instruction execution system, apparatus, or device. The computer readable storage medium may include, but is not limited to, an electronic, magnetic, optical, electromagnetic, infrared, or semiconductor system, apparatus, or device, or any suitable combination of the foregoing. Alternatively, the computer readable storage medium may be a machine readable signal medium. More specific examples of a machine-readable storage medium would include an electrical connection based on one or more wires, a portable computer diskette, a hard disk, a Random Access Memory (RAM), a read-only memory (ROM), an erasable programmable read-only memory (EPROM or flash memory), an optical fiber, a portable compact disc read-only memory (CD-ROM), an optical storage device, a magnetic storage device, or any suitable combination of the foregoing.
To provide for interaction with a user, the systems and techniques described here can be implemented on a vehicle having: a display device (e.g., a CRT (cathode ray tube) or LCD (liquid crystal display) monitor) for displaying information to a user; and a keyboard and pointing device (e.g., a mouse or a trackball) by which a user can provide input to the vehicle. Other kinds of devices may also be used to provide for interaction with a user; for example, feedback provided to the user may be any form of sensory feedback (e.g., visual feedback, auditory feedback, or tactile feedback); and input from the user may be received in any form, including acoustic input, speech input, or tactile input.
The systems and techniques described here can be implemented in a computing system that includes a background component (e.g., as a data server), or that includes a middleware component (e.g., an application server), or that includes a front-end component (e.g., a user computer having a graphical user interface or a web browser through which a user can interact with an implementation of the systems and techniques described here), or any combination of such background, middleware, or front-end components. The components of the system can be interconnected by any form or medium of digital data communication (e.g., a communication network). Examples of communication networks include: local Area Networks (LANs), wide Area Networks (WANs), blockchain networks, and the internet.
The computing system may include clients and servers. The client and server are typically remote from each other and typically interact through a communication network. The relationship of client and server arises by virtue of computer programs running on the respective computers and having a client-server relationship to each other. The server can be a cloud server, also called a cloud computing server or a cloud host, and is a host product in a cloud computing service system, so that the defects of high management difficulty and weak service expansibility in the traditional physical hosts and VPS service are overcome.
It should be appreciated that various forms of the flows shown above may be used to reorder, add, or delete steps. For example, the steps described in the present invention may be performed in parallel, sequentially, or in a different order, so long as the desired results of the technical solution of the present invention are achieved, and the present invention is not limited herein.
The above embodiments do not limit the scope of the present invention. It will be apparent to those skilled in the art that various modifications, combinations, sub-combinations and alternatives are possible, depending on design requirements and other factors. Any modifications, equivalent substitutions and improvements made within the spirit and principles of the present invention should be included in the scope of the present invention.
Claims (10)
1. An EGR rate control method, characterized by comprising:
when the current engine working condition is confirmed to be in a stable state, a first EGR rate, a second EGR rate, a first engine air inflow corresponding to the first EGR rate and a first engine exhaust gas amount are obtained, and a first oxygen concentration detected by a feed-forward oxygen sensor under the control of the first EGR rate and a second oxygen concentration detected by the feed-forward oxygen sensor under the control of the second EGR rate are obtained;
determining an actual oxygen concentration difference from the first oxygen concentration and the second oxygen concentration, and determining a first theoretical oxygen concentration value from the first oxygen concentration, the first EGR rate, the second EGR rate, the first engine intake air amount, and the first engine exhaust gas amount;
and determining whether the second EGR rate control is correct according to the actual oxygen concentration difference value and the first theoretical oxygen concentration value, and judging whether to adjust the second EGR rate according to the second oxygen concentration after determining that the second EGR rate control is correct.
2. The EGR rate control method according to claim 1, characterized in that the first EGR rate is smaller than the second EGR rate;
determining an actual oxygen concentration difference from the first oxygen concentration and the second oxygen concentration, comprising:
and subtracting the first oxygen concentration from the second oxygen concentration to obtain an oxygen concentration as an actual oxygen concentration difference.
3. The EGR rate control method according to claim 1, characterized in that determining a first theoretical oxygen concentration value from the first oxygen concentration, the first EGR rate, the second EGR rate, the first engine intake air amount, and the first engine exhaust gas amount includes:
the first theoretical oxygen concentration value is determined according to the following formula:
m 1 ·Δγ＝m 2 ·(β-α)·(21％-γ1)
wherein Δγ1 is the first theoretical oxygen concentration value; alpha is the first EGR rate; beta is the second EGR rate; γ1 is the first oxygen concentration; m is m 1 Exhausting the first engine amount; m is m 2 An intake air amount for the first engine.
4. The EGR rate control method according to claim 1, characterized in that determining whether the second EGR rate control is correct based on the actual oxygen concentration difference and the first theoretical oxygen concentration value includes:
determining an EGR rate control judgment range according to the first theoretical oxygen concentration value;
if the actual oxygen concentration difference value is in the EGR rate control judgment range, determining that the second EGR rate is correctly controlled;
and if the actual oxygen concentration difference value is not in the EGR rate control judgment range, determining that the second EGR rate control is wrong.
5. The EGR rate control method according to claim 1, characterized by further comprising, before determining whether to adjust the second EGR rate based on the second oxygen concentration:
and acquiring a second engine air inflow and a second engine exhaust gas amount corresponding to the second EGR rate, and determining a second theoretical oxygen concentration value according to the second oxygen concentration, the first EGR rate, the second engine air inflow and the second engine exhaust gas amount.
6. The EGR rate control method according to claim 5, characterized in that determining whether to adjust the second EGR rate based on the second oxygen concentration includes:
if the second oxygen concentration is higher than the second theoretical oxygen concentration value, increasing the second EGR rate;
and if the second oxygen concentration is lower than the second theoretical oxygen concentration value, reducing the second EGR rate.
7. The EGR rate control method according to claim 6, characterized by further comprising, after increasing the second EGR rate:
acquiring an updated EGR rate, and acquiring an updated oxygen concentration detected by a feed-forward oxygen sensor under control of the updated EGR rate, the updated EGR rate being greater than the second EGR rate;
determining an updated actual oxygen concentration difference based on the second oxygen concentration and the updated oxygen concentration, and determining an updated theoretical oxygen concentration value based on the second oxygen concentration, the second EGR rate, the updated EGR rate, the second engine intake air amount, and the second engine exhaust gas amount;
and determining whether the updated EGR rate control is correct according to the updated actual oxygen concentration difference value and the updated theoretical oxygen concentration value.
8. An EGR rate control apparatus, comprising:
the data acquisition module is used for acquiring a first EGR rate, a second EGR rate, a first engine air inflow corresponding to the first EGR rate and a first engine exhaust gas amount when the current engine working condition is confirmed to be in a stable state, and acquiring a first oxygen concentration detected by a feed-forward oxygen sensor under the control of the first EGR rate and a second oxygen concentration detected by the feed-forward oxygen sensor under the control of the second EGR rate;
an oxygen concentration value determination module that performs determination of an actual oxygen concentration difference based on the first oxygen concentration and the second oxygen concentration, and determines a first theoretical oxygen concentration value based on the first oxygen concentration, the first EGR rate, the second EGR rate, the first engine intake air amount, and the first engine exhaust air amount;
and the EGR rate control module is used for determining whether the second EGR rate control is correct according to the actual oxygen concentration difference value and the first theoretical oxygen concentration value, and judging whether the second EGR rate is adjusted according to the second oxygen concentration after determining that the second EGR rate control is correct.
9. A vehicle, characterized in that the vehicle comprises:
at least one processor; the method comprises the steps of,
a memory communicatively coupled to the at least one processor; wherein,
the memory stores a computer program executable by the at least one processor to enable the at least one processor to perform the EGR rate control method according to any of claims 1-7.
10. A computer readable storage medium, characterized in that the computer readable storage medium stores computer instructions for causing a processor to execute the EGR rate control method according to any one of claims 1 to 7.
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| CN202311798021.8A CN117703610A (en) | 2023-12-25 | 2023-12-25 | EGR rate control method and device, vehicle and storage medium |
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